Studies of the Toxicological Potential of Tripeptides (L-Valyl-L-prolyl-L-proline and L-lsoleucyl-L-prolyl-L-proline): VI. Effects of Lactobacillus helveticus-fermented Milk Powder on Fertility and Reproductive Performance of Rats
| Autor: | Takahiro Kurosaki, Bruce K. Bernard, John H. Mennear, Masafumi Maeno |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Cultured Milk Products Offspring 010501 environmental sciences Biology Toxicology 030226 pharmacology & pharmacy 01 natural sciences Fetal Development Rats Sprague-Dawley 03 medical and health sciences Sex Factors 0302 clinical medicine Pregnancy Internal medicine Lactation Copulation Toxicity Tests medicine Animals Sexual maturity Kidney Pelvis 0105 earth and related environmental sciences Epididymis Estrous cycle Fetus Dose-Response Relationship Drug Reproduction Body Weight Organ Size medicine.disease Lactobacillus helveticus Rats Fertility Endocrinology medicine.anatomical_structure Animals Newborn In utero Gestation Female Powders Oligopeptides |
| Zdroj: | International Journal of Toxicology. 24:61-89 |
| ISSN: | 1092-874X 1091-5818 |
| Popis: | The objective of these studies was to assess the effects of the tripeptides, L-valyl-L-prolyl-L-proline (VPP) and L-isoleucyl-L-prolyl-L-proline (IPP), on reproductive capabilities of male and female rats. The specific goals of the experiments were (1) to determine the effects of orally administered tripeptides on (a) fertility and reproductive behavior in both sexes of rats, (b) embryo-fetal development in pregnant rats, and (c) pre- and postnatal development of rats exposed to tripeptides in utero and during lactation; and (2) to estimate the no-observable-adverse-effect doses of tripeptides in maternal and fetal rats. During the conduct of these classical segment I, II, and III studies, the test material was powdered Lactobacillus helveticus-fermented milk (FM), which contains the tripeptides, VPP and IPP. FM (0, 500, 1000 or 2000 mg/kg body weight [BW]/day—equivalent to 0, 0.8, 1.6, or 3.3 mg/kg BW/day of VPP plus IPP) was administered to males by oral gavage from 4 weeks prior to mating until sacrifice, and to females from 2 weeks prior to mating through day 20 of lactation. Evaluative parameters included monitoring grossly observable clinical signs; food consumption and body weight gains; mating behavior and fertility indices of both sexes; implantation and maintenance of embryos; sex ratio of live pups ; fetal viability; incidences of external, visceral or skeletal variations; growth and behavioral development; as well as reproductive capabilities of Fi offspring exposed to FM during gestation and lactation. All animals were subjected to macroscopic examination at termination of their segment of the studies. Clinical signs, body weights, and food consumption were unaffected by administration of FM. During segment I, the test agent had no effect on estrus cycle, mating behavior, fertility index, or reproductive competence of either males or females. The results of segment II experiments revealed no effects of FM on postimplantation survival-loss, sex ratio or birth weights of live fetuses, and there was no evidence of treatment-associated developmental or teratological effects. During segment III, FM was without effect on pup viability, behavioral and sexual maturation, and reproductive capability of the F1 generation. Under the conditions of these experiments, the no-observable-adverse-effect level (NOAEL) of FM on reproductive performance in male and female rats is greater than 2000 mg/kg BW/day, the equivalent of 3.3 mg/kg BW/day of VPP plus IPP. |
| Databáze: | OpenAIRE |
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