Abstract
The effects of mechanical sensory stimulation (by pinching, brushing or pressing) of either a hindpaw or a hind leg on ovarian blood flow measured by laser Doppler flowmetry were studied in anesthetized non-pregnant adult female rats. Pinching of a hindpaw and pressing of a hind leg were effective stimuli for the ovarian blood flow. Pinching of a hindpaw increased blood pressure and ovarian sympathetic nerve activity, and decreased ovarian blood flow. The decrease response in ovarian blood flow following pinching of a hindpaw was reversed to the increase response after surgical severance of ovarian sympathetic nerves. Pressing of a hind leg decreased blood pressure, ovarian sympathetic nerve activity and ovarian blood flow. The response of decrease in ovarian blood flow following pressing of a hind leg was slightly augmented after severance of ovarian sympathetic nerves. Electrical stimulation of the distal part of the severed splanchnic nerve at the left side decreased the left ovarian blood flow, and this response was abolished by i.v. injection of phentolamine, the α-adrenoceptor antagonist. The present results demonstrate that ovarian blood flow increase or decrease passively to responses of an increase or a decrease in systemic arterial blood pressure following mechanical sensory stimulation of a hindlimb, and these passive responses of ovarian blood flow are modulated by reflexive activity of ovarian sympathetic vasoconstrictor nerves to attenuate blood pressure-dependent passive changes in ovarian blood flow. [Jpn J Physiol 54 Suppl:S201 (2004)]
