Expression and distribution of GABA and GABAB-receptor in the rat adrenal gland.

The inhibitory effects of gamma-aminobutyric acid (GABA) in the central and peripheral nervous systems and the endocrine system are mediated by two different GABA receptors: GABAA-receptor (GABAA-R) and GABAB-receptor (GABAB-R). GABAA-R, but not GABAB-R, has been observed in the rat adrenal gland, where GABA is known to be released. This study sought to determine whether both GABA and GABAB-R are present in the endocrine and neuronal elements of the rat adrenal gland, and to investigate whether GABAB-R may play a role in mediating the effects of GABA in secretory activity of these cells. GABA-immunoreactive nerve fibers were observed in the superficial cortex. Some GABA-immunoreactive nerve fibers were found to be associated with blood vessels. Double-immunostaining revealed GABA-immunoreactive nerve fibers in the cortex were choline acetyltransferase (ChAT)-immunonegative. Some GABA-immunoreactive nerve fibers ran through the cortex toward the medulla. In the medulla, GABA-immunoreactivity was seen in some large ganglion cells, but not in the chromaffin cells. Double-immunostaining also showed GABA-immunoreactive ganglion cells were nitric oxide synthase (NOS)-immunopositive. However, neither immunohistochemistry combined with fluorescent microscopy nor double-immunostaining revealed GABA-immunoreactivity in the noradrenaline cells with blue-white fluorescence or in the adrenaline cells with phenylethanolamine N-methyltransferase (PNMT)-immunoreactivity. Furthermore, GABA-immunoreactive nerve fibers were observed in close contact with ganglion cells, but not chromaffin cells. Double-immunostaining also showed that the GABA-immunoreactive nerve fibers were in close contact with NOS- or neuropeptide tyrosine (NPY)-immunoreactive ganglion cells. A few of the GABA-immunoreactive nerve fibers were ChAT-immunopositive, while most of the GABA-immunoreactive nerve fibers were ChAT-immunonegative. Numerous ChAT-immunoreactive nerve fibers were observed in close contact with the ganglion cells and chromaffin cells in the medulla. The GABAB-R-immunoreactivity was found only in ganglion cells in the medulla and not at all in the cortex. Immunohistochemistry combined with fluorescent microscopy and double-immunostaining showed no GABAB-R-immunoreactivity in noradrenaline cells with blue-white fluorescence or in adrenaline cells with PNMT-immunoreactivity. These immunoreactive ganglion cells were NOS- or NPY-immunopositive on double-immunostaining. These findings suggest that GABA from the intra-adrenal nerve fibers may have an inhibitory effect on the secretory activity of ganglion cells and cortical cells, and on the motility of blood vessels in the rat adrenal gland, mediated by GABA-Rs.

γ-Aminobutyric acid B receptor immunoreactivity in the mouse adrenal medulla.

The present study examined gamma-aminobutyric acid B (GABAB ) receptor, GABA, choline acetyltransferase (ChAT), and neuronal nitric oxide synthase (nNOS) immunoreactivities in the mouse adrenal medulla. GABAB receptor immunoreactivity was seen in numerous chromaffin cells and in a few ganglion cells of the adrenal medulla. By using a formaldehyde-induced fluorescence (FIF) method, GABAB receptor immunoreactivity was observed in numerous adrenaline (A) cells, but not in noradrenaline (NA) cells showing blue-white fluorescence. This suggests that GABAB receptors may be present in the A cells and be related to the secretory activity of A cells but not NA cells in the mouse adrenal medulla. GABAB receptor immunoreactive ganglion cells were shown to be nNOS immunopositive by using a double immunostaining method. Weak GABA immunoreactivity was visible in some chromaffin cells and in the numerous nerve fibers of the medulla. By using the FIF method, weak GABA-immunoreactive chromaffin cells were shown to be in the NA cells showing blue-white fluorescence. GABA-immunoreactive nerve fibers were in dense contact in A cells, but not NA cells. GABA-immunoreactive nerve fibers closely contacted a few ganglion cells. Numerous GABA-immunoreactive nerve fibers in the medulla showed ChAT immunoreactive. This result suggests that GABA and acetylcholine may be released from the same nerve fibers and may have a secretory effect on the A cells of the medulla.

[Epidural labor analgesia for a primipara with schizophrenia].

A 32-year-old primipara, who had been diagnosed as schizophrenia for a year and with good control of the disease by olanzapine administration, requested epidural labor analgesia. Olanzapine is an atypical antipsychotic, and is contraindicated to use with epinephrine, because the a receptor antagonistic action of olanzapine decreases the blood pressure in combination with epinephrine. Hypotention is one of the major complications during the labor epidural analgesia. In addition, this patient is at high risk of hypotension under antipsycotic medication. As hypotension leads to placental-fetal circulation insufficiency, extreme attention to prevent hypotension and to preserve uteroplacental blood flow should be paid. Olanzapine was discontinued before two days of the induction. Sufficient hydration with crystalloid was given beforehand to avoid hypotention. Both phenylephrine and norepinephrine were ready for an anticipated hypotention. Oxytocin infusion began after an epidural catheter was placed at L2-3 intervertebral space. She delivered a healthy baby under good pain control. Apgar score of the baby was 9 and 9 at 1 and 5 minutes after birth, respectively. Total volume of infusion was 2000 ml. No mental disturbance was observed during the labor and delivery. The patient and her baby were discharged on the 4th day postpartum.

[Attempt to offer safe and effective epidural analgesia for labor pain at the Hamamatsu University Hospital].

The anesthesiologists began offering epidural analgesia for labor pain at the Hamamatsu University Hospital in cooperation with the obstetricians and the midwives in August, 2005. It is necessary for anesthesiologists to concentrate on caring of the parturients in order to offer safe and effective labor epidural analgesia. We discussed how to begin and continue to offer the labor epidural based on our experience while the number of anesthesiologists is insufficient.

[Case of facial edema and tongue swelling after aortic surgery in the lateral position].

The facial edema and tongue swelling after oral surgery are not rare complications and many case reports were published, but they were limited after anesthesia for surgery of other parts. A 70-year-old woman who had underwent thoraco-abdominal aortic graft surgery showed severe facial edema and tongue swelling after the surgery in the right lateral position. The tongue was largely protruded outside of the mouse when entering ICU and was gradually improved. Twelve hours later, the tongue was shrunken into the mouse. The patient was moved to a general ward without any complications on the 5th postoperative day. The patient had taken anti-hypertensive drugs including candesartan for a long period. She might have become susceptible to angioedema by angiotensin receptor blocker such as angiotensin-converting enzyme inhibitor and stress of surgery, and anesthesia might have induced a complication of the acute tongue swelling. Although, prevention and treatment of angioedema have not been established, careful observation would be required.