Twelve-month evaluation of rhesus monkey dams and infants after relaxin (HRLX-2) infusion in late pregnancy

• Published in: Reproductive toxicology (Elmsford, N.Y.) Vol. 10; no. 1; pp. 29 - 36
• Main Authors: Golub, Mari S., Galiher, Norma J., Working, Peter K., Greenspan, Adam
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 1996; Elsevier
• Subjects: Analysis of Variance; Animals; Antibodies - analysis; Biological and medical sciences; Birth Weight - drug effects; Body Height - drug effects; Body Temperature - drug effects; development; Drug toxicity and drugs side effects treatment; Female; fertility; Fertilization - drug effects; Follow-Up Studies; growth; infant; Infusions, Intravenous; Longitudinal Studies; Macaca mulatta; Medical sciences; Miscellaneous (drug allergy, mutagens, teratogens...); monkeys; Muscle Tonus - drug effects; neonate; Pharmacology. Drug treatments; Pregnancy; Pregnancy Outcome; Pregnancy, Animal; Prenatal Exposure Delayed Effects; Random Allocation; relaxin; Relaxin - administration & dosage; Relaxin - immunology; Relaxin - toxicity; toxicology; toxicology; monkeys; development; pregnancy; fertility; relaxin; neonate; growth; infant; Relaxine; Intravenous administration; Toxicity; Monkey; Harmlessness; Ovarian hormone; Protein hormone; Progeny; Vertebrata; Mammalia; Term pregnancy; Animal; Primates; Teratogen
• ISSN: 0890-6238; 1873-1708
• DOI: 10.1016/0890-6238(95)02015-2

Pregnant rhesus monkeys received daily i.v. infusions of chemically synthesized human relaxin (hRlx-2) (0.1 mg/kg/day N = 6, 2.0 mg/kg/day N = 6, vehicle control N = 7) from the onset of cervical softening to delivery (0 to 14 infusions) to simulate potential therapeutic use of this agent for cervical ripening. Reproductive fitness of dams was evaluated during the next breeding season, and infants were studied through 12 months of age. Birth weight and size, neonatal heart rate and body temperature and neurobehavioral status were not influenced by intrauterine relaxin exposure. Neonatal muscle tone was greater and responsiveness was lower in the hRlx-2 treated infants than in controls. No group differences were seen in infant postnatal growth, maturation or incidence of health problems. Maternal endpoints including uterine involution, resumption of menses, conception rate, and pregnancy outcome were similar across groups. Systemic exposure of rhesus monkeys to relatively high levels of hRLx-2 in late pregnancy did not have apparent long term effects for the measures evaluated under conditions of the experiment. Conclusions concerning adverse effects are limited by the small sample size.