Renin-aldosterone axis and arginine-vasopressin responses to sodium depletion in camels.

Urinary output, urinary sodium and potassium excretion, plasma electrolyte concentrations and osmolality, plasma renin activity (PRA), and plasma aldosterone and arginine-vasopressin (AVP) concentrations were determined in eight camels in Tadla (Morocco). After administration of furosemide (2 mg.kg-1 body wt) urinary water, sodium and potassium excretions increased, inducing hypovolemia (as reflected by 14.

Rat myoblast fusion requires exteriorized m-calpain activity.

Our previous studies demonstrated that fibronectin could be proteolyzed by m-calpain during muscle cell differentiation. Recent results indicated also that m-calpain could be exteriorized and more particularly associated to extracellular matrix components. To clarify one of the possible physiological functions of this proteinase during myogenesis, we have analyzed the incidence of added purified m-calpain and calpain inhibitors on the fusion kinetics of cultured myoblasts.

Hormonal control of water and sodium in plasma and urine of camels during dehydration and rehydration.

Eight dromedary camels were studied for 24 days under control conditions (3 days), and during water deprivation (14 days) and rehydration (7 days) in Tadla (Morocco), during the summer. During dehydration, food intake gradually fell and was zero on the last day and animals lost about 30% of their body weight. However, most of this reduction in weight was attributed to water loss, since body weight of the animals returned to control values following rehydration.

Renin-aldosterone system and arginine vasopressin in diarrhoeic calves.

Plasma renin activity, plasma aldosterone and arginine-vasopressin concentrations were determined in five diarrhoeic and five healthy newborn calves. In animals suffering from diarrhoea these three parameters were 10-15 times higher than those observed in controls. These results suggest that the hormonal systems that control fluid and electrolyte homeostasis are highly stimulated by dehydration and salt depletion induced by faecal losses of water and sodium in calves affected with diarrhoea.