I has been informed that stimulation with electroacupuncture of the points PC.5 y PC.6 reduces the neuronal cardiovascular sympathic premotory activity in the ventrolateral rostral marrow (VLrM) and the respuestas presoras reflejas viscerales.

The authors suggest that the VLrM spinal region plays an important role in the specific in situ inhibition on the cardiovascular reactions induced by acupuncture.

Various authors have informed that the inhibitory effect of electroacupuncture in the pressor reaction induced by bradicicine in cats and the subsequent  improvement in the ischemic was dependent on the activation of the opioids receptors, in a specific way, the receptors located in the ventrolateral rostral marrow (VLrM) and this inhibiting effect was reverted by the intravenous application of naloxona (Chao et al, 1999). Also, it has been informed that the inhibitory effect of electroacupuncture in the pressor reflex induced by bradicinine applied in the gall bladder is partly due to the activation of opioid receptors, probably located in the ventrolateral rostral marrow (VLrM).

The relationship between the effects of electroacupunture and specific subtypes of opioid receptors and the related neurotransmitters has been studied. In anesthesized cats it was found that electroacupunture of PC.5-PC.6 tempered the rise in the arterial pressure triggered by the  application of bradicinine in the gall bladder. Then antagonists of the opioid receptors subtypes were applied to the VLrM. The antagonists of receptors mu- and delta- CTOP e ICI 178,824, respectively, diminished significantly the inhibition induced by electroacupuncture. The antagonist of the receptor-K (nor-BNI) was less effective and had a shorter action.

In the same way that with electroacupuncture, the  microinjection of opioid agonists mu- and delta, DAGO y DADLE, respectively, in the VLrM diminished significantly the presor reactions. ON the contrary, the agonist opioid kappa, U50,488 failed in modifying the pressor reaction induced by bradicinine. The authors conclude that a  significant part of the inhibition of  the pressor reaction of the gall bladder by electroacupuncture is related to the activation of the receptors mu- and delta- in the VLrM. In this way, the endogenous neurotransmitters of the receptors mu- and delta-, beta-endorphines and encephalines, in the VLrM, seem to play a role in the modulation of the cardiovascular reflex reactions modulated by electroacupuncture. On the contrary, it seems less probable that dinorphine is related with this reaction.

It has been informed that acupuncture can diminish arterial pressure in patients with hypertension and that this diminution may be caused at least partly to endocrine mechanisms. Chiu et al researched the effect of acupuncture on the arterial pressure and the secretion of rennin, vasopressin and cortisol in hypertense patients with no prior treatment. It was found that after the application of acupuncture the systolic and diastolic pressure, the cardiac frequency, and the activity of plasmatic rennin diminished. No changes were found in the concentrations of plasmatic vasopressin or cortisol. These results suggest according to the authors that acupuncture diminishes arterial pressure at least partly due to the diminution in the secretion of rennin.

In a model of acute miocardiac ischemia in rats caused by the link in the descending anterior left branch of the coronary artery electroacupuncture on the point PC.6 diminished the damage of diverse cardiac functions originated by the cardiac ischemia as by the diminution of the cardiac frecuency, the medial arterial pressure, the systolic ventricular pressure, among others. After the microinjection of nitro-L-arginine, an inhibitor of the sintetasa of nitric oxide in the ventrolateral rostral marrow the homeostatic effect of the electroacupuncture was reduced or abolished in PC.6. These results suggested that the effect of the stimulation in PC.6 es possibly mediated by the nitric oxide in the ventrolateral rostral marrow.

In a similar way, it was demonstrated that the hypotensive and bradicardic responses provoked by electroacupuncture of E.36 were modified by changes in the synthesis of nitric oxide by-product from L-arginine in the gracilis nucleous and concluded that nitric oxide is the mediator in the cardiovascular secondary reactions to electroacupuncture on E.36 related to the gracilis nucleous.

Acupuncture and renal y suprarenal functions

Lee et al made research on the effect of acupuncture on healthy volunteers on plasmatic levels of various hormones measured by radioinmunoensayo. They found that acupuncture on V.23 diminished the plasmatic levels of auricular immunereactive peptid natriurethic and diminished the plasmatic activity of renin. While V.15 increased the plasmatic  levels of auricular immunereactive peptid natriurethic, in addition it diminished the plasmatic levels of aldosterone. These facts prove that specific points of acupuncture can exert specific regulating actions in the hormonal levels and this way contribuye in the regulation of the hydroelecrolythic balance.

Electroacupuncture and emotional circuit

It has been proven that electroacupuncture can activate beta- endorphinergic and noradrenergic neurones that is thrown in the ventrolateral rostral marrow (VLrM), these last ones acting on the interneurones VLR-GABAergic, in this way producing a depressor effect.

Ku et al showed that the depressor effect of electroacupuncture was strong enough to surpass the pressor response of the emotional circuit. (central amigdaloid nucleous); they also informed that the application of beta-endorphine and GABA in the VLrM mediated the antagonism of electroacupuncture, and in this way the effect of electroacupuncture did not develop in the emotional circuit and the paraventricular nucleous, two key nuclei in addition to the VLRM, that also receive que beta-EPergic information in the emotional circuit.