Non-Genomic Actions of Testosterone Metabolites on Uterine Contractility in Rats
Year: 2026
Type: article
Abstract: Background: Sex hormones play crucial functions in the body via the genomic and non-genomic pathways. 5α- and 5β-dihydrotestosterone (5α- and 5β-DHT) are 5-reduced testosterone metabolites. We aimed to investigate the non-genomic effect of 5α- and 5β-DHT on uterine muscle contractility in vitro and in vivo for non-pregnant and 22-day-pregnant rats. Methods: The rapid in vitro action of 5α-DHT and 5β-DHT (10−9–10−3 M) on KCl (25 mM)-stimulated contractions was examined in an organ bath in the presence of several blockers and after endometrium removal. The actions of DHTs (10−4 M) and nifedipine (10−7 M) were also examined in contractions stimulated by KCl (40 mM) with a cumulative addition of CaCl2 (3–120 mM). Plasma DHT levels were measured by ELISA after a single intraperitoneal (i.p.) administration of DHT (10 mg/kg), and kinetic curves were obtained. The in vivo relaxing action of DHTs was detected by strain-gauge sensors. The animals received 5α- or 5β-DHT alone (3/10/30/100/300 mg/kg i.p.) or with flutamide (100 mg/kg i.p.). Results: DHT showed concentration-dependent relaxation of uterine muscle in vitro, with a higher potency observed for 5β-DHT. Among the blockers used, G15 and L-NAME reduced the potency of 5α-DHT in pregnant rats only. Both DHTs inhibited the contraction-increasing effect of CaCl2, proving their Ca2+ inhibiting effects. DHTs had similar cmax and tmax values in both non-pregnant and pregnant rats. DHT plasma levels before and 30 min after administration were proportional to the administered doses. Their single doses (30/100/300 mg/kg) elicited a flutamide-resistant uterine relaxing effect in vivo. Conclusions: DHTs or their analogs are candidates for further studies in the human uterus to establish their potential to treat conditions associated with uterine hyperactivity.
Source: Pharmaceutics
Authors: Saif-alnasr H. Mohammed, Ayman B. Mousa, Mohammed Taj-Eldin Abdalla, Anita Sztojkov-Ivanov, Kálmán F. Szűcs, Róbert Gáspár
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,499
OpenAlex ID: W7204254767
