Placentophagia and the Tao of POEF.

Placentophagia, ingestion of placenta and amniotic fluid, usually during parturition, is a behavioral feature of nearly all nonaquatic, placental mammals, and is a nexus for several interlocking behavioral phenomena. Placentophagia has not been typical of human cultures, but in recent years, some women in affluent societies have engaged in it, thereby bringing publicity to the behavior. First, we summarized benefits of placentophagia for nonhuman mammals, which include increased attractiveness of neonates, enhanced onset of maternal behavior, suppression of pseudopregnancy, and enhancement of opioid hypoalgesia by Placental Opioid-Enhancing Factor (POEF), a benefit that may extend well outside the context of parturition.

Placentophagia in humans and nonhuman mammals: causes and consequences.

Afterbirth ingestion by nonhuman mammalian mothers has a number of benefits: (1) increasing the interaction between the mother and infant; (2) potentiating pregnancy-mediated analgesia in the delivering mother; (3) potentiating maternal brain opioid circuits that facilitate the onset of caretaking behavior; and (4) suppressing postpartum pseudopregnancy. Childbirth is fraught with additional problems for which there are no practical nonhuman animal models: postpartum depression, failure to bond, hostility toward infants. Ingested afterbirth may contain components that ameliorate these problems, but the issue has not been tested empirically.

Low doses of risperidone and morphine interact to produce more analgesia and greater extrapyramidal effects in rats.

The search for non-narcotic drugs that will enhance the analgesic effects of opiates without enhancing their side effects has included the investigation of psychoactive drugs already approved for other uses. Some research has supported an analgesic effect of risperidone (RIS), an atypical neuroleptic. However, the analysis of the analgesic efficacy of RIS alone or as an adjuvant to morphine (MOR) has not considered the production of adverse motor effects that would limit its usefulness as a treatment for pain.

Evaluation of buprenorphine in a postoperative pain model in rats.

We evaluated the commonly prescribed analgesic buprenorphine in a postoperative pain model in rats, assessing acute postoperative pain relief, rebound hyperalgesia, and the long-term effects of postoperative opioid treatment on subsequent opioid exposure. Rats received surgery (paw incision under isoflurane anesthesia), sham surgery (anesthesia only), or neither and were treated postoperatively with 1 of several doses of subcutaneous buprenorphine. Pain sensitivity to noxious and nonnoxious mechanical stimuli at the site of injury (primary pain) was assessed at 1, 4, 24, and 72 h after surgery.

Lack of analgesic efficacy in female rats of the commonly recommended oral dose of buprenorphine.

Previous work in our laboratory showed that the recommended oral dose of buprenorphine (0.5 mg/kg) was not as effective as the standard therapeutic subcutaneous dose for postoperative analgesia in male Long-Evans (hooded) and Sprague-Dawley (albino) rats. The aim of the current study was to extend this analysis to female rats.

Placenta ingestion by rats enhances delta- and kappa-opioid antinociception, but suppresses mu-opioid antinociception.

Ingestion of placenta or amniotic fluid produces a dramatic enhancement of centrally mediated opioid antinociception in the rat. The present experiments investigated the role of each opioid receptor type (mu, delta, kappa) in the antinociception-modulating effects of Placental Opioid-Enhancing Factor (POEF-presumably the active substance). Antinociception was measured on a 52 degrees C hotplate in adult, female rats after they ingested placenta or control substance (1.

Dopaminergic and glutamatergic mechanisms mediate the induction of FOS-like protein by cocaethylene.

Cocaethylene is a psychoactive metabolite formed during the combined consumption of cocaine and ethanol. As this metabolite has many properties in common with cocaine, it is conceivable that cocaethylene administration may induce the activity of nuclear transcription factors that regulate the expression of late-response genes. Therefore, the temporal induction of FOS-like protein in rat brain was examined following IP administration of 60 micromol/kg cocaethylene.

The effect of SRI 63-675, a competitive platelet-activating factor receptor-antagonist, in the generalized Shwartzman reaction.

Evidence indicates a role for platelet-activating factor (PAF) in endotoxin (LPS)-induced shock. To determine its involvement in LPS-induced intravascular coagulation, we assessed the efficacy of SRI 63-675, a specific PAF receptor antagonist, to prevent fibrin deposition in the various organs of New Zealand White rabbits 4 h after two intravenous doses of LPS (100 micrograms/kg), spaced 24 h apart. SRI 63-675 significantly lowered peak tumor necrosis factor levels after LPS challenge.

The effect of pregnancy on the response to the TxA2/PGH2 analogue U-46619 in rabbits.

We compared the hemodynamic actions of U-46619, a stable thromboxane A2 (TxA2) prostaglandin H2 (PGH2) analogue, in nonpregnant (NP) rabbits with those observed in late pregnant (P) rabbits. An intravenous injection of U-46619 (10 micrograms) to each of eight NP chronically instrumented rabbits (mean body weight 3.4 kg) induced an immediate (1 min) and reversible fall of cardiac output (CO, 66%) and mean arterial pressure (MAP, 41%, both P < 0.

Mononuclear cells in glomeruli and cytokines in urine reflect the severity of experimental proliferative immune complex glomerulonephritis.

Immunohistochemical methods were used to investigate the role of macrophages in the progression of proliferative immune complex glomerulonephritis. The mononuclear cell component of glomerular inflammation was analysed in three different stages of chronic serum sickness, each of which was clearly distinguished by criteria of kidney function. Urinary excretion of the macrophage secretory products interleukin-1 and tumour necrosis factor was also evaluated in relation to the functional severity of kidney disease.