OBJECTIVE: An investigation of excitatory vascular responses in the human ovarian vein, a blood vessel normally exposed to high concentrations of ovarian steroid hormones and capable of adaptation to circulatory changes associated with reproductive life. DESIGN: Pharmacological responses of surgical specimens of human ovarian vein to electrical field stimulation of sympathetic nerves, noradrenaline, alpha,beta-methylene adenosine 5'-triphosphate (alpha,beta-MeATP), endothelin-1 (ET-1), and 5-hydroxytryptamine (5-HT) were studied. Comparisons were made between in vitro pharmacological responses and the diagnostic category, age, smoking status, reproductive history and hormonal status of patients. SETTING: Research laboratory. RESULTS: Maximal contractile responses in longitudinal preparations, expressed as a percentage of the response to potassium chloride 125 mmol l-1, were 28% (SE 7.2) to electrical field stimulation and 107% (SE 15.1) to noradrenaline. In ring preparations, maximal responses to various agents were: noradrenaline 93% (SE 10.2); 5-HT 79% (SE 8.0); alpha,beta-MeATP 48% (SE 8.4); and ET-1 87% (SE 10.1). pD2(-log EC50) values for noradrenaline were 5.82 (SE 0.21) in longitudinal preparations and 5.65 (SE 0.10) in ring preparations; for ET-1 in ring preparations these values were 7.88 (SE 0.74). Responses to sympathetic nerve stimulation were attenuated by the adrenoceptor antagonist phentolamine; any residual responses were blocked by desensitisation of P2-purinoceptors with alpha,beta-MeATP or the addition of suramin, indicating that noradrenaline and adenosine 5'-triphosphate may be co-transmitters in these nerves. pD2 values for 5-HT were 5.97 (SE 0.12) in specimens from unsterilised patients (n = 19) compared with 5.20 (SE 0.24) in specimens from those who had previously undergone sterilisation (n = 6) (P < 0.05). No other relation between clinical characteristics and pharmacological responses were detected and, in particular, there were no apparent changes associated with ageing or hormonal status. CONCLUSIONS: Three main conclusions may be drawn from this study: (1) adenosine 5'-triphosphate is a co-transmitter in sympathetic nerves in the human ovarian vein; (2) tubal sterilisation affects vascular responsiveness to 5-HT; and (3) ovarian steroid hormones are likely to influence sympathetic vascular control via effects on catecholamine and adenosine 5'-triphosphate synthesis, storage, release, degradation or re-uptake, rather than via effects on vascular smooth muscle receptors.
OBJECTIVE: An investigation of excitatory vascular responses in the humanovarian vein, a blood vessel normally exposed to high concentrations of ovarian steroid hormones and capable of adaptation to circulatory changes associated with reproductive life. DESIGN: Pharmacological responses of surgical specimens of humanovarian vein to electrical field stimulation of sympathetic nerves, noradrenaline, alpha,beta-methylene adenosine 5'-triphosphate (alpha,beta-MeATP), endothelin-1 (ET-1), and 5-hydroxytryptamine (5-HT) were studied. Comparisons were made between in vitro pharmacological responses and the diagnostic category, age, smoking status, reproductive history and hormonal status of patients. SETTING: Research laboratory. RESULTS: Maximal contractile responses in longitudinal preparations, expressed as a percentage of the response to potassium chloride 125 mmol l-1, were 28% (SE 7.2) to electrical field stimulation and 107% (SE 15.1) to noradrenaline. In ring preparations, maximal responses to various agents were: noradrenaline 93% (SE 10.2); 5-HT 79% (SE 8.0); alpha,beta-MeATP 48% (SE 8.4); and ET-1 87% (SE 10.1). pD2(-log EC50) values for noradrenaline were 5.82 (SE 0.21) in longitudinal preparations and 5.65 (SE 0.10) in ring preparations; for ET-1 in ring preparations these values were 7.88 (SE 0.74). Responses to sympathetic nerve stimulation were attenuated by the adrenoceptor antagonist phentolamine; any residual responses were blocked by desensitisation of P2-purinoceptors with alpha,beta-MeATP or the addition of suramin, indicating that noradrenaline and adenosine 5'-triphosphate may be co-transmitters in these nerves. pD2 values for 5-HT were 5.97 (SE 0.12) in specimens from unsterilised patients (n = 19) compared with 5.20 (SE 0.24) in specimens from those who had previously undergone sterilisation (n = 6) (P < 0.05). No other relation between clinical characteristics and pharmacological responses were detected and, in particular, there were no apparent changes associated with ageing or hormonal status. CONCLUSIONS: Three main conclusions may be drawn from this study: (1) adenosine 5'-triphosphate is a co-transmitter in sympathetic nerves in the humanovarian vein; (2) tubal sterilisation affects vascular responsiveness to 5-HT; and (3) ovarian steroid hormones are likely to influence sympathetic vascular control via effects on catecholamine and adenosine 5'-triphosphate synthesis, storage, release, degradation or re-uptake, rather than via effects on vascular smooth muscle receptors.