Abnormal autonomic nervous system function in rural Thai men: A potential contributor to their high risk of sudden unexplained nocturnal death syndrome.

Background: Rural compared to urban Thai populations have a higher incidence of sudden unexplained nocturnal death syndrome (SUNDS). This study tests the hypothesis that compared to young urban Thai men, the young rural northeast Thai men display autonomic system dysfunction that may contribute to their relatively high risk to develop SUNDS.

Methods: Forty-seven healthy second and third year students from Khon Kaen University (20-22years old) were divided into central, urban northeastern, and rural northeastern groups, based on the locality in which they had grown up and in which their parents had lived prior to their birth.

Perinatal taurine exposure programs patterns of autonomic nerve activity responses to tooth pulp stimulation in adult male rats.

Perinatal taurine excess or deficiency influences adult health and disease, especially relative to the autonomic nervous system. This study tests the hypothesis that perinatal taurine exposure influences adult autonomic nervous system control of arterial pressure in response to acute electrical tooth pulp stimulation. Female Sprague-Dawley rats were fed with normal rat chow with 3% β-alanine (taurine depletion, TD), 3% taurine (taurine supplementation, TS), or water alone (control, C) from conception to weaning.

Impaired renal response to portal infusion of hypertonic saline in adriamycin-treated rats.

1. The hepatorenal reflex plays an important role in water and salt homeostasis by matching renal excretion to gastrointestinal absorption. This homeostatic mechanism is impaired in nephrotic rats.

Adult renal function is modified by perinatal taurine status in conscious male rats.

Perinatal taurine exposure influences renal function in adult female offspring. This study tests the hypothesis that prenatal rather than postnatal taurine exposure alters renal function in adult conscious male rats. Female Sprague Dawley rats were fed normal rat chow and tap water alone (Control), tap water containing 3% beta-alanine (taurine depletion, TD) or tap water containing 3% taurine (taurine supplementation, TS) either from conception until delivery (fetal period; TDF or TSF) or from delivery until weaning (lactation period; TDL or TSL).

High sugar intake via the renin-angiotensin system blunts the baroreceptor reflex in adult rats that were perinatally depleted of taurine.

Perinatal taurine depletion leads to several physiological impairments in adult life, in part, due to taurine's effects on the renin-angiotensin system, a crucial regulator of growth and differentiation during early life. The present study tests the hypothesis that perinatal taurine depletion predisposes adult female rats to impaired baroreceptor control of arterial pressure by altering the renin-angiotensin system. Female Sprague Dawley (SD) rats were fed normal rat chow and from conception to weaning drank 3% beta-alanine in water (taurine depletion, TD) or water alone (Control, C).

Perinatal taurine exposure alters renal potassium excretion mechanisms in adult conscious rats.

Perinatal taurine exposure has long-term effects on the arterial pressure and renal function. This study tests its influence on renal potassium excretion in young adult, conscious rats. Female Sprague-Dawley rats were fed normal rat chow and given water alone (C), 3% beta-alanine in water (taurine depletion, TD) or 3% taurine in water (taurine supplementation, TS), either from conception until delivery (fetal period; TDF or TSF) or from delivery until weaning (lactation period; TDL or TSL).

High sugar intake exacerbates cardiac reperfusion injury in perinatal taurine depleted adult rats.

Perinatal taurine depletion and high sugar diets blunted baroreflex function and heightens sympathetic nerve activity in adult rats. Cardiac ischemia/reperfusion also produces these disorders and taurine treatment appears to improve these effects. This study tests the hypothesis that perinatal taurine exposure predisposes recovery from reperfusion injury in rats on either a basal or high sugar diet.

Perinatal taurine alters arterial pressure control and renal function in adult offspring.

The present study investigates the effect of perinatal taurine exposure on renal function in adult, female rats on a high sugar diet. Perinatal taurine depleted (TD), supplemented (TS) or untreated control (C) female offspring were fed normal rat chow and tap water (CW,TDW or TSW) or tap water with 5% glucose (CG, TDG or TSG) after weaning. At 7-8 weeks of age, renal function was studied in the conscious, restrained rats.

Sex dependent effects of perinatal taurine exposure on the arterial pressure control in adult offspring.

The present study tests the sex-dependent effect of perinatal taurine exposure on arterial pressure control in adults. Female Sprague-Dawley rats were fed normal rat chow with 3% beta-alanine (taurine depletion,TD), 3% taurine (taurine supplementation,TS) or water alone (C) from conception to weaning. Their male and female offspring were then fed normal rat chow and tap water with 5% glucose (C with glucose, CG; TD with glucose, TDG; TS with glucose, TSG) or water alone (CW, TDW or TSW).

Perinatal taurine depletion increases susceptibility to adult sugar-induced hypertension in rats.

This study tests the hypothesis that perinatal taurine depletion produces autonomic nervous system dysregulation and increases arterial pressure in young male rats maintained on a high sugar diet. Sprague-Dawley dams were either taurine depleted (beta-alanine 3% in water) or left untreated from conception to weaning. Their male offspring were fed normal rat chow with or without 5% glucose.

Changes in erythrocyte contents of potassium, sodium and magnesium and Na, K-pump activity after the administration of potassium and magnesium salts.

Low potassium and magnesium status and decreased Na, K-pump activity is an endemic condition among rural Northeast Thais. The authors examined the effect of supplementing potassium and magnesium on erythrocyte potassium, sodium and magnesium content and on Na, K-pump activity. Rural Northeast Thai renal stone patients (62) were recruited, divided into four groups and supplemented for one month with potassium chloride (Group1, n = 16), potassium-sodium citrate (Group2, n = 15), chelated magnesium (Group 3, n =16) and potassium-magnesium citrate (Group 4, n =15) in order to achieve 40 mmol potassium, 10 mmol magnesium and 60 mmol citrate daily.

Excess dietary glucose alters renal function before increasing arterial pressure and inducing insulin resistance.

Background: Diets high in carbohydrates are associated with hypertension, activation of the renin-angiotensin system, hyperinsulinemia, insulin resistance, and renal dysfunction. This study tests the hypothesis that the initial effect of a long-term high carbohydrate diet is a renin-angiotensin system dependant impairment of renal function.

Methods: Three-week-old male Sprague-Dawley rats drank water containing 5% glucose or water alone.

Diuretic effects of selected Thai indigenous medicinal plants in rats.

Extracts of five indigenous Thai medicinal having ethnomedical application in the treatment of dysuria were investigated for their diuretic activity. Root extracts of Ananas comosus and Carica papaya, given orally to rats at a dose of 10 mg/kg, demonstrated significantly increased urine output (P < 0.01) which was 79 and 74%, respectively, of the effect of an equivalent dose of hydrochlorothiazide.

Mitogenic activity of rat salivary glands after electrical stimulation of parasympathetic nerves.

Electrical stimulation of the parasympathetic innervation to parotid or submandibular gland for 30 or 60 min resulted in increased [3H]thymidine uptake of both glands when measurements were made 18 h later. With 30 min of stimulation, the mean increase in parotid was 30% compared with unstimulated mates, and after 60 min of stimulation, the increase was 76%. Stimulation for 30 min with the adrenergic antagonists propranolol and phenoxybenzamine present showed an increase in [3H]thymidine of 76%.

Effects of autonomic antagonists and growth factors on activity-mediated hyperplasia of rat parotid.

Administration of the autonomic antagonists atropine (1 mg/kg body wt), propranolol (2 mg/kg body wt), and phenoxybenzamine (2 mg/kg body wt) before the dietary change from all liquid to solid chow prevented an increase in uptake of [3H]thymidine into DNA of rat parotid gland associated with this dietary change. Administration of either the cholinergic antagonist alone or the adrenergic antagonists alone produced partial inhibition. The effects of complete autonomic blockade were not reversed when nerve growth factor (NGF) or epidermal growth factor (EGF) was given immediately after administration of antagonists.

Effects of carbamylcholine and isoproterenol on electrolyte fluxes in perfused main duct of submandibular gland of reserpinized rat.

Administration of reserpine (RES) at a dosage of 0.5 mg/kg body wt, ip daily for 7 days was found to lower the dose of carbamylcholine and isoproterenol that alters sodium and potassium transport by cells of the main duct of rat submandibular gland. In the perfused main excretory duct of the submandibular gland of the RES rat, administration of carbamylcholine at a dosage of 1 microgram/kg body wt, inhibited net efflux of sodium (17%) and administration of isoproterenol at a dosage of 2 micrograms/kg body wt increased net efflux of sodium (20%); these drugs, at the same dosages, did not induce significant change in electrolyte flux of normal rat.

Effects of PGE1 alone and on sympathetically mediated Na, K transport in the perfused main submandibular duct of rat.

PGE1 was administered in 5 micrograms/kg doses every 5 min over a period of 70 min and Na and K transport in the perfused main duct of rat submandibular gland was examined during a period without stimulation of the sympathetic nerve as well as during stimulation of the sympathetic nerve. A 25% decrease in the amount of Na absorbed and a 42% decrease in the amount of K secreted occurred when PGE1 alone was administered; the same change occurred when the sympathetic nerve was stimulated in the presence of PGE1. These data show, for the first time, an effect of PGE1 alone on electrolyte transport, and suggest that specific PGE1 receptors are activated.

Effects of saliva from chronically reserpinized rat on Na and K transport in perfused main excretory duct of submandibular gland of normal rat.

Reserpine (RES) (0.5 mg/kg body wt, ip) was administered to rats for 7 days. On Day 8 saliva was evoked from these animals by intraperitoneal injection of pilocarpine nitrate (10 mg/kg body wt) and saliva from submandibular and parotid glands was collected separately.

Effects of alpha, beta 1, and beta 2 adrenergic antagonists on the Na and K concentrations of sympathetic-nerve stimulated rat saliva.

Selective alpha and beta 1 and beta 2 adrenergic antagonists were used with electrical stimulation of the sympathetic innervation to parotid and submandibular glands of rats in order to delineate the role of the beta 1 and beta 2 adrenoceptors in regulation of salivary flow rate, Na reabsorption and K secretion from these glands. In parotid gland, [Na] of sympathetically evoked saliva in the presence of phentolamine (3 mg/kg, i.p.

Effects of sympathetic nerve stimulation in the presence of specific adrenergic antagonists on Na, K, and Cl transport in perfused rat submandibular duct.

The role of beta 1- and beta 2-adrenoceptors in the modification of Na, K, and Cl transport in submandibular main duct of rat perfused with bicarbonate saline solution was studied with direct sympathetic nerve stimulation (4 V, 5 ms, 20 Hz) in the presence of specific adrenergic antagonists. Nerve stimulation in the presence of phenoxybenzamine (3 mg/kg b. wt.

Effects of electrical stimulation of the sympathetic nerve on the levels of beta-adrenergic and cholinergic muscarinic receptors and cyclic nucleotides in rat salivary glands.

After 30 and 60 min of stimulation, there were decrease of 16 to 19 per cent in beta-adrenoceptors in rat submandibular and parotid glands; a 10-min stimulation caused no change. Pre-incubation of the reaction mixtures (stimulated glands) with atenolol, a beta 1-antagonist, prevented most dihydroalprenolol (DHP) binding, but with butoxamine, a beta 2-antagonist, DHP binding was nearly complete. Thus the beta-receptor was of the beta 1-subtype.

Modification of dobutamine- and terbutaline-induced calcium and fluid secretion from rat salivary glands by atenolol and butoxamine.

Saliva was elicited from rat salivary glands by terbutaline at i.p. doses of 1, 5, 10 and 25 mg/kg b.

Effects of adrenergic agonists on electrolyte transport in perfused salivary duct of rat.

The Na and Cl absorption and K secretion that occur in the main duct of rat submandibular gland are affected by adrenergic actions. The specific effects of stimulation of alpha-, beta 1- and beta 2-adrenergic receptors on net transepithelial fluxes of Na, K and Cl were investigated in microperfused main excretory duct of rat submandibular gland. Administration of methoxamine (2.

Effects of substance P on Na and K transport in perfused main submandibular duct of rat.

Substance P (2 and 4 micrograms/kg . min, iv) caused an inhibition of net efflux of Na and net influx of K in perfused main excretory duct of rat submandibular gland. These effects could not be blocked by atropine sulfate.

Secretory responses to autonomic stimulation of rat salivary glands following reserpine treatment.

The response to stimulation of the parasympathetic innervation to parotid or submandibular glands of reserpinized rats was altered from that of untreated rats. Thus, acute reserpinization, like other types of sympathectomy, resulted in increase in volume of parasympathetically-evoked parotid or submandibular saliva when comparison was made with evoked saliva from untreated glands. As norepinephrine is depleted by reserpine, there was no response to stimulation of sympathetic nerves to these reserpinized glands.