Effects of low dosages of apomorphine on maternal responsiveness in lactating rats.

Lactating rats (day 7 +/- 1 postpartum) were observed during a 1-h reunion with their pups 4 h after separation from them and 10 min after subcutaneous injection of saline (SAL; 0.1 ml) or low dosages of the dopamine agonist, apomorphine (APO; 0.1 or 0.25 mg/kg). Although APO did not affect latency to sniff pups or retrieve the first pup, there were dosage-dependent delays in onset of licking and nursing pups, and decreases in retrieval and grouping of pups, nursing duration, and litter weight gain. The alterations in maternal responsiveness among APO-treated dams were related to increased carrying and mouthing of pups and markedly increased sniffing of pups, bedding, and cage. Duration of time spent licking pups, exploring, and self-grooming did not differ between groups. Thus, certain APO-induced stereotypic behaviors interfered with the normal sequence of maternal behavior by exaggerating some components and delaying others. These results are relevant to disturbances in maternal behavior caused by hyperreactivity or by other drugs that increase dopaminergic activity, such as cocaine.

Effects of garlic thioallyl derivatives on growth, glutathione concentration, and polyamine formation of human prostate carcinoma cells in culture.

This study investigated whether naturally occurring garlic derivatives and synthetic S-cysteinyl compounds that resemble garlic constituents have antiproliferative effects on human prostate carcinoma (LNCaP) cells. Studies also examined whether S-allylmercaptocysteine and S-allylcysteine affect two important molecular targets, namely reduced glutathione and polyamines. Results showed that S-allylmercaptocysteine (50 mg/L) diminished LNCaP cell growth whereas the antiproliferative effect of S-allylcysteine was not as pronounced. Studies using synthetic S-cysteinyl analogues revealed that growth inhibition was most effective with compounds containing a disulfide or an active diallyl moiety. Marginal to no inhibitory effect was observed with monosulfinic analogues. Both S-allylmercaptocysteine and S-allylcysteine caused an increase in LNCaP cell reduced glutathione concentrations. Putrescine and spermine concentrations decreased and spermidine increased 3 d after S-allylmercaptocysteine treatment. At 5 d after S-allylmercaptocysteine treatment, polyamine concentrations were similar to those of saline-treated controls. Diminished cell growth and altered polyamine concentrations suggest that S-allylmercaptocysteine may impede the polyamine synthesizing enzyme, ornithine decarboxylase, either by enhancing the formation of reduced glutathione, a known inhibitor of ornithine decarboxylase, or by reacting directly with ornithine decarboxylase at its nucleophilic thiol moiety. Because S-allylcysteine also increases reduced glutathione formation but does not significantly inhibit growth, the latter mechanism may be more likely for this compound. These data provide further evidence that nonessential nutrients derived from garlic may modulate tumor growth. Further research is required on effects of garlic derivatives in vivo before information from the present studies can be used to assist in the development of effective nutritional strategies for preventing progression of prostate cancer.