To investigate possible permanent consequences of an early postnatal overfeeding, the following experimental model was used: Male Wistar rats were divided into three groups after birth: (1) Small litters with 3-4 newborns (overnutrition), (2) normal litters with 12 animals (normonutrition), and (3) large litters with 20-24 newborn rats (undernutrition). After weaning all animals had free access to tap water and standard pellet diet. The serum insulin level of animals from small litters on day 15 of life was highly significantly increased as compared to the other groups. These overfed hyperinsulinaemic rats showed a higher body weight gain during the suckling period trough juvenile life until adulthood, associated with enhanced mean food intake and resulting in an increased relative body weight (per body length) as a sign of obesity. The obesity was found to be correlated with basal hyperinsulinaemia and increased systolic blood pressure in the small-litter-adults. Moreover, the early postnatally overnourished animals developed an increased type I-like diabetes susceptibility to a "subdiabetogenic" dose of streptozotocin in adulthood. These results suggest once more that hyperinsulinism during brain differentiation, in the present experiment induced by early postnatal overnutrition, may represent a predisposing factor for the development of obesity, of increased diabetes susceptibility and also of increased cardiovascular risk in later life.
Newborn male Wistar-rats received bilateral intrahypothalamic insulin-agar-implants on the 2nd or 8th day of life. In male control animals only the insulin-free indifferent agar-vehicle was implanted at the same age. In both experimental groups with temporary intrahypothalamic hyperinsulinism during brain organization the following results were obtained: 1) Higher body weight gain starting at the end of the hypothalamic differentiation period and continuing during juvenile life until adulthood, resulting in increased relative body weight as a sign of obesity; 2) A tendency to basal hyperinsulinaemia in juvenile and adult age; 3) Impaired glucose tolerance in adulthood; 4) Increased diabetes susceptibility to a single "subdiabetogenic" dose of streptozotocin in adult age. In view of these and previous observations a teratogenetic role of high insulin concentrations during the organization of glucoregulatory hypothalamic structures is hypothesized and the possible relevance of such hyperinsulinism as a predisposing factor for a lifelong enhanced diabetes and/or obesity risk is suggested.
We investigated in this study the response of the fetal hypothalamo-pituitary-adrenal (HPA) system during an acute maternal stress in rats, in order to find out a possible role of developing fetal hypothalamus and to correlate its function to the androgen unbalance during the critical period of sex-specific brain differentiation. Pregnant rats of days 18-22 of gestation were subjected to an acute forced immobilization, and plasma levels of corticosterone (B) and ACTH were measured in mothers and fetuses. Hypothalamic contents of CRH and beta-endorphin (EP), pituitary content of ACTH, and plasma levels of B and ACTH were measured in mothers and fetuses under the maternal stress on day 20 of gestation. By an acute exposure to the 20 minutes' stress, plasma levels of B and ACTH elevated significantly in mothers on each day of gestation. A significant increase of fetal plasma ACTH was detected from day 18 in males, and from day 20 in females. During the maternal stress on day 20 of gestation, hypothalamic contents of CRH and EP decreased significantly in male and female fetuses, when plasma levels of B and ACTH elevated significantly. These results indicate that fetal HPA axis seems to actually respond to the maternal stress during the late gestational period. Further, a release of CRH under the stress together with an activation of EP system in the fetal hypothalamus suggests a possible mechanism regulating the androgen secretion by the fetal hypothalamus via changes of the LH levels.
Impaired renal function increases total tamsulosin plasma concentration by approximately 100% after single-dose administration and in steady state. Since active unbound drug levels are not affected, no dose modification is required in symptomatic BPH patients with renal impairment.
Migration of human spermatozoa in cervical mucus obtained from women shortly before mid-cycle was studied, using an in-vitro method for horizontal sperm penetration. The results indicate that a small number of Y-bearing spermatozoa form the frontal zone during active migration.A deviation of sex ratio depending on the time of conception during the menstrual cycle has been postulated on the basis of clinical observations and, more recently, of differential migration of X-and Y-bearing spermatozoa (Fürst
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.