ELIASSON, MONA; MEYERSON, BENGT J
Comparison of the action of lysergic acid diethylamide and apomorphine on the copulatory response in the female rat.
Psychopharmacology; 1976 Vol 49(3) 301-306
Studied the effects of LSD and apomorphine on copulatory behavior (lordosis) in ovariectomized estrogen + progesterone-treated female Sprague-Dawley rats. Each compound inhibited lordosis behavior in a dose-dependent manner and with a similar time course. Pimozide (0.1 and 0.5 mg/kg) blocked the apomorphine-(0.2 mg/kg)-induced decrease in the lordosis response, while only a certain abbreviation of the LSD (0.10 mg/kg) inhibition was achieved by pimozide (0.5 mg/kg). Chlorpromazine (0.5 mg/kg) in a dose without effects on lordosis had an action similar to pimozide on the LSD effect. It is concluded that the predominant action of LSD on the female copulatory response is not mediated by increased dopamine receptor activity, but that the LSD effect might be modulated by decreased dopaminergic activity.
ELIASSON, MONA
Actions of repeated injections of LSD and apomorphine on the copulatory response of female rats.
Pharmacology, Biochemistry and Behavior; 1976 Dec Vol 5(6) 621-625
LSD inhibits the lordosis response in the ovariectomized and estrogen + progesterone-treated female rat. The same effect is obtained by apomorphine. Tolerance develops to certain responses after repeated injections of LSD, and the present study compared the influence of apomorphine and LSD when given in repeated doses. Possible cross-tolerance between the 2 compounds was also tested on the frequency of lordosis responding in ovariectomized and hormone-treated female Sprague-Dawley rats. Tolerance to LSD developed over 7 days, while the suppressing influence of apomorphine on lordosis in 7 repeated doses was not significantly altered from that of a single dose. No cross-tolerance was observed on the lordosis response with either order of treatments. Repeated doses of LSD did not influence locomotor activity differently from a single dose, while repeated doses of apomorphine enhanced this response in comparison with the effect of an acute dose. Results indicate differential sensitivity to the repeated treatments and provide further support for an interpretation of the LSD effects on lordosis responding to be primarily on serotonergic rather than dopaminergic receptors.
Huang et al, "Induction of estrous cycles in old non-cyclic rats by progesterone, ACTH, ether stree, or L-dopa.
" Neuroendocrin.
20: p21-34, 1976.
Topic: Bromocriptine, prosexual substances, nootropics
Sandoval, Y; Komisaruk, B; Beyer, C
Possible role of inhibitory glycinergic neurons in the regulation of lordosis behavior in the rat.
Pharmacology, Biochemistry and Behavior; 1988 Feb Vol 29(2) 303-307
Strychnine sulfate was bilaterally infused into the ventromedial hypothalamic nucleus (VMH) of ovariectomized sexually inexperienced rats primed 40 hrs earlier with estradiol benzoate (EB). EB induced only weak lordosis behavior (LB) in 25% of the Ss. Strychnine in 3 and 9 mug dosages induced intense LB but not proceptivity in most estrogen-primed Ss. Ovariectomized adrenalectomized EB-primed Ss also displayed significant LB following infusion of 9 mug of strychnine into the VMH. Administration of 5 mug EB followed 40 hrs later by 2 mg of progesterone elicited intense LB. Results suggest that in the VMH, strychnine facilitates LB in EB-primed rats by removing a tonic inhibitory effect exerted by glycinergic neurons on VMH neurons.
Sietnieks A; Meyerson BJ.
Enhancement by progesterone of 5-hydroxytryptophan inhibition of the copulatory response in the female rat.
Neuroendocrinology (Switzerland). 35(5): p321-6, 1982.
Topic: L-Dopa, prosexual substances, aphrodisiacs
SU TP; SHUKLA K; GUND T
Steroid binding at sigma receptors: CNS and immunological implications.
Ciba Found Symp. 1990; 153: 107-13; discussion 113-6
The sigma receptor has been suggested to be the mediator of the psychomimetic effects induced by certain benzomorphan opioids and phencyclidine. Potent sigma receptor ligands include haloperidol and other 'atypical' potential antipsychotic drugs. The sigma receptor is found in the central nervous system and also in the immune and endocrine systems. Gonadal and adrenal steroids such as progesterone, testosterone, deoxycorticosterone and corticosterone were found to be competitive inhibitors of binding of the sigma receptor ligand [3H] d-SKF-10,047. The sigma receptor is not the traditionally recognized cytosolic progesterone receptor and is found in crude membrane fractions. Results from molecular modelling using geometric fitting and electrostatic potential calculations suggested that the molecular skeleton of steroid hormones shares common features with prototypic sigma ligands such as d-SKF-10,047 and that the oxygen of the C-20 carbonyl group on these steroids may represent a critical 'pharmacophore' for their interactions with sigma receptors. Comparison of the affinities of steroids at sigma receptors with their efficacies is an anti-inflammatory test yielded a striking qualitative correlation. Taken Taken together these results suggest that sigma receptors may mediate certain aspects of steroid-induced mental disturbances and alterations in immune function.