A dopamine agonist stimulates progesterone secretion from adrenal gland

Progesterone attenuates cocaine-induced responses

In this review, we summarize literature focused on how progesterone alters cocaine-induced psychomotor, reinforcement, and physiological responses. Clinical studies suggest that progesterone attenuates the subjective effects of cocaine. Similarly, preclinical studies have demonstrated that cocaine-induced reward and psychomotor responses are attenuated after progesterone administration. In rats progesterone also reduces the reinforcement effects of cocaine attenuates acquisition, escalation, reinstatement of cocaine self-administration, and cocaine-seeking behaviors. Progesterone also counteracts the facilitatory effects of estrogen on cocaine self-administration and psychomotor activation. These findings suggest that progesterone has a potential in clinical applications as a treatment for cocaine addiction. Constantly changing progesterone serum levels in female humans and rats affect the female's reinforcement responses to cocaine and may in part contribute to the known sex differences in cocaine responses.

Progesterone receptors activation after acute cocaine administration

Cocaine modulates serum levels of progesterone in intact female and male rats, as well as in pregnant dams, and progesterone decreases or attenuates cocaine-induced behavioral and reward responses. It has been postulated that cocaine's modulation of serum progesterone levels may in turn alter progesterone receptor activity, thereby contributing to cocaine-induced alterations of neuronal functions and genomic regulations. To test this hypothesis, intact male rats received acute injections of saline or cocaine (15 or 30 mg/kg, dissolved in 0.9% saline, intraperitoneal). Progesterone serum levels, progesterone receptor (PR) protein levels, and PR-DNA binding complexes were measured in the striatum by radioimmunoassay, Western blot, and gel shift analyses, respectively. After injection of 15 mg/kg of cocaine, induction of progesterone serum levels was closely followed by an increase in receptor protein levels and DNA binding complexes. After injection of 30 mg/kg of cocaine, similar effects were observed along with an attenuation of receptor protein levels and DNA binding complexes at 60 min. Our results suggest that activation of progesterone receptors may be a mechanism by which cocaine mediates behavior through molecular alterations in the central nervous system.

Why are women from Venus and men from Mars when they abuse cocaine?

Both preclinical and clinical studies have shown sexually dimorphic patterns in behavioral responses to cocaine in all phases of the cocaine addiction process (induction, maintenance, and relapse). Thus, a clear picture is emerging which suggests that the biological basis of sex-specific differences in cocaine addiction resides in the disparate regulation of the CNS by male and female gonadal hormones. This review discusses the role that gonadal hormones play in these sexually dimorphic patterns of behavioral responses to cocaine.

Effects of dopaminergic drugs on plasma levels of steroid hormones in conscious dogs

Progesterone, cortisol and testosterone levels were measured by radioimmunoassay in peripheral venous blood of conscious dogs. I.v. injections of the dopamine receptor agonists apomorphine (0.05 mg/kg) and bromocriptine (0.1 mg/kg) increased progesterone levels (and cortisol levels, as previously shown) in dogs of both sexes. The response to apomorphine was abolished by pretreatments with peripheral dopamine receptor antagonists (domperidone and halopemide). Progesterone and cortisol responses to the dopamine receptor agonists were parallel, but the ratio of concentration was 1/100. Testosterone levels were not modified. These results suggest that the dopamine receptor agonists stimulate progesterone release from the adrenal glands at a site functionally accessible to the peripheral dopamine receptor antagonists. In addition, the neuroleptic haloperidol (0.1 mg/kg) was shown to cause long lasting increases of progesterone levels.