The sympathetic nervous system affects the susceptibility and course of Trypanosoma cruzi infection.

Trypanosoma cruzi (T. cruzi) is an intracellular parasite that causes Chagas' disease, a major health problem in Latin America. Using a murine model of infection with this parasite, we have previously shown that corticosterone blood levels are markedly elevated during the course of the disease in C57Bl/6 male mice and that this increase is protective for the host by restricting the production of pro-inflammatory cytokines. Since the hypothalamus-pituitary-adrenal (HPA) axis usually operates in a concerted way with the sympathetic nervous system (SNS), we have now studied whether noradrenergic nerves can affect the course of T. cruzi infection and the sexual dimorphism observed in the disease. We found a decreased splenic noradrenaline concentration and content, paralleled by a reduction in noradrenergic nerve fibers in the spleen of infected mice, and increased HPA axis activity. These alterations were more marked in males than in females. When the spontaneous loss of noradrenergic nerve fibers was advanced by chemical sympathectomy prior to infection, males died earlier and mortality significantly increased in females. Chemical denervation did not significantly affect the concentration of specific IgM and IgG2a antibodies to T. cruzi, and did not worsen myocarditis, but resulted in increased parasitemia and IL-6 and IFN-γ blood levels. The results obtained in this model of parasitic disease provide further indications of the relevance of interactions between the immune system and the SNS for host defense.

Uso do Ligasure na esplenectomia por videocirurgia em cães / The use of ligasure in splenectomy by laparoscopic surgery in dog

Na cirurgia laparoscópica, a hemostasia através da confecção de ligaduras vasculares é um fator limitante, realizamos esplenectomia em seis cães, utilizando um novo equipamento de coagulação bipolar, o Ligasure, visando uma melhor performance nos resultados das hemostasias realizadas. Os resultados foram satisfatórios não havendo complicações pós-operatória(AU)

In the laparoscopic surgery, the hemostasis through the vascular ligatures is a limiting factor. In this study, a new coagulation equipment, the Ligassure, was used in six splenectomies, to improve the hemostasis effects. The results were good and post-surgical complications were not observed(AU)

Uso do Ligasure na esplenectomia por videocirurgia em cães / The use of ligasure in splenectomy by laparoscopic surgery in dog

Na cirurgia laparoscópica, a hemostasia através da confecção de ligaduras vasculares é um fator limitante, realizamos esplenectomia em seis cães, utilizando um novo equipamento de coagulação bipolar, o Ligasure, visando uma melhor performance nos resultados das hemostasias realizadas. Os resultados foram satisfatórios não havendo complicações pós-operatória

In the laparoscopic surgery, the hemostasis through the vascular ligatures is a limiting factor. In this study, a new coagulation equipment, the Ligassure, was used in six splenectomies, to improve the hemostasis effects. The results were good and post-surgical complications were not observed

Effect of secretion of splenocytes after superior ovarian nerve section on the ovarian steroidogenesis.

It is known that ovary and spleen are innervated extensively by afferent and efferent noradrenergic sympathetic nerve fibers from the celiac ganglion. Furthermore, immune cells located in the ovary influence the ovarian physiology. However, the peripheral interaction between the immune and neuroendocrine system is poorly understood. This work was undertaken to study the effect of superior ovarian nerve (SON) transection, in adult rats, on the number of splenocyte beta-adrenergic receptors and their possible relation to ovarian steroidogenesis, measuring the effect of secretions of those splenocytes on progesterone and estradiol release from the ovary. Seven days after SON transection, the splenocytes were isolated and then cultured for 48 h. Their number of beta-adrenergic receptors, measured using [125I]-cyanopindolol as ligand, increased, and their culture media, used to stimulate ovaries from 60-day-old intact (neither SON-transected nor sham-operated) rats in vitro on diestrous day 2 showed a decrease in progesterone release and an increase in estradiol release in relation to splenocyte culture media of control rats (sham-operated; p < 0.001, respectively). The effects of in vivo SON transection were simulated by an in vitro system modulating the splenocyte beta-adrenergic receptor number. The splenocytes from SON-transectioned rats were preincubated with and without norepinephrine (NE) 10(-6) M for 48 h, a low and high number of beta-adrenergic receptors respectively, and then were stimulated with NE 10(-6) M for 24 h. After that, the culture medium from splenocytes with a low number of beta-adrenergic receptors induced progesterone release from the ovaries of intact rats (p < 0. 001), but produced no change in estradiol release. The data suggest that splenocyte secretions, which participate in the ovarian steroidogenic response, particularly in progesterone release, might be controlled by adrenergic influences since the number of splenocyte beta-adrenergic receptors changes through SON-celiac ganglion-noradrenergic postganglionic innervation of the spleen. In estradiol release, probably other neurotransmitters than norepinephrine (NE) are involved when the SON is sectioned. In this paper we also show functional evidence for modulation of immune function by the sympathetic nervous system and its principal neurotransmitter, NE.

[Central and peripheral mechanisms of hypotension induced by dl-propranolol in the dog]. / Mecanismo central y periférico de la hipotensión producida por el dl-propranolol en el perro.

The IV injection of 1-2 mg/kg dl-propranolol in dogs elicited a reduction of arterial blood pressure accompanied by a blockade of hypertensive responses to carotid occlusion or stimulation of the central trunk of the vagus. The same fall of blood pressure and identical blockades were seen following propranolol injected in the cisterna magna at a total dose of 2-5 mg. This late treatment also abolished the hypertensive response to KCl injected into the cisterna magna. On the other hand, propranolol failed to modify significantly responses to the electrical stimulation of hepatic and splenic sympathetic fibers and did not influence the hypertensive effects of adrenaline and noradrenaline. These findings are compatible with the notion that propranolol lowers systemic blood pressure via an action on central nervous system vasomotive centers.