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Biomedical subjects

V K Reddy

Publications and source records attributed to V K Reddy.

35 records · Page 2Linked to original sources
PubMed1989

Spinally projecting noradrenergic neurons of the dorsolateral pontine tegmentum: a combined immunocytochemical and retrograde labeling study.

Two to three days following injection of horseradish peroxidase (HRP) into the spinal cords of 5 cats, the animals were sacrificed and perfused, and the brainstems removed and sectioned. The sections were then processed for HRP and, immunocytochemically, for tyrosine hydroxylase (TH). The dorsolateral pontine tegmentum was divided into the locus coeruleus, subcoeruleus and Kölliker-Fuse nucleus; the mean percentage of pontospinal neurons containing TH were found to be 85.5 +/- 2.5 (S.E.M.), 79.6 +/- 5.6 and 87.1 +/- 3.1, respectively. The cell diameters of locus coeruleus cells were also measured.

Adrenergic Fibers↗
PubMed1987

Serotonergic and non-serotonergic raphe neurons projecting to the feline lumbar and cervical spinal cord: a quantitative horseradish peroxidase-immunocytochemical study.

A quantitative study of raphe-spinal neurons and serotonergic neurons in 3 medullary raphe nuclei in the cat indicates that more than 80% of the raphe-spinal neurons that project to the spinal cord are serotonergic raphe-spinal neurons in each of the nuclei. More than 85% of the descending raphe-spinal neurons in the two caudal nuclei, nucleus raphe pallidus and nucleus raphe obscurus, are serotonergic, whereas 75% of the raphe-spinal neurons in the more rostrally placed nucleus raphe magnus contain serotonin (5-HT). These results are discussed in relation to descending systems containing both neuropeptides and 5-HT and collateralizing to several spinal segments.

Animals↗
PubMed1987

Differential labeling of the vestibular complex following unilateral injections of horseradish peroxidase into the cat and rat locus coeruleus.

Following unilateral injections of horseradish peroxidase into the cat and rat locus coeruleus (LC), bilateral retrograde labeling was evident in all 4 vestibular nuclei. In both species, the major contributions of LC afferents arose from the ipsilateral rather than the contralateral vestibular nuclei. Quantitative analysis in the rat has indicated that approximately 90% of the total vestibular-LC projections originated from the ipsilateral vestibular nuclear complex, with 10% from the contralateral. The frequency distribution was in the order of lateral greater than medial greater than superior greater than inferior vestibular nuclei.

Animals↗
PubMed1982

Effect of histamine on blood flow to the adrenal glands of pigs.

Blood flow to the adrenal glands was measured with radioactive microspheres labeled with 85Sr in 25-37 kg pigs following the intravenous infusion of physiological saline solution or histamine solution (2 micrograms/kg/min) for 60 minutes. Total blood flow averaged 2.28 ml/min/gland for control pigs and 4.38 ml/min/gland for histamine-treated pigs (P less than .0005). Mean blood flow to the adrenal glands of histamine-treated pigs (3.15 ml/min/g) was 82% higher than that of control pigs (1.73 ml/min/g); the difference was highly significant (P less than .0005). The result of this study showed that histamine caused an increased blood flow to the porcine adrenal glands.

Adrenal Glands↗
PubMed1982

Localization of the sacral parasympathetic nucleus in the dog.

The extent and location of the sacral parasympathetic nucleus was studied in 6 dogs, using light microscopy. After interruption of the pelvic nerve, chromatolytic somata were observed in thionin-stained transverse serial sections (15 mum) of appropriate spinal cord segments. Maps of the sacral parasympathetic nucleus were made by plotting the chromatolytic somata in drawings of the transverse sections of the spinal cord. The sacral parasympathetic nucleus was observed in all 3 sacral segments of the spinal cord, and in 1 dog, it also extended into the spinal cord segment Ca1. The cranial end of the nucleus was contained in the caudal one-third of spinal segment S1. The location of the caudal end was variable: it was within the middle one-third of spinal cord segment S3 in 4 dogs, in the caudal one-third of spinal cord segment S3 in 1 dog, and in the cranial one-third of spinal cord segment Ca1 in 1 dog. The densest clusters of somata of this nucleus were in the middle and caudal one-third of spinal cord segment S2. The somata, for the most part, were in the intermediolateral gray column and in the lateral funiculus. A small number of isolated somata also were in the intermediomedial gray column.

Animals↗
PubMed1981

Effect of histamine and prostaglandin E2 on gastric blood flow in swine.

Gastric blood flow was measured by the radioactive microspheres entrapment technique following the IV infusions of saline solution, histamine, or prostaglandin E2 and histamine to young pigs. Pigs treated with histamine (2 micrograms/kg/minute for 60 minutes) had significantly higher blood flow to the gastric mucosa (P less than 0.025), particularly to the region of the proper gastric (fundic) glands (P less than 0.01), than did the saline-treated pigs. When prostaglandin E2 (1 microgram/kg/minute for 60 minutes) was infused simultaneously with histamine, there was a slight, but not significant, decrease (P less than 0.10) in mucosal blood flow to the region of the proper gastric glands. Analysis of the percentage distribution of blood flow indicated that the increase in blood flow to the region of the proper gastric glands after histamine infusion may be due to a redistribution of blood flow from the cardiac gland region.

Animals↗
PubMed1981

Regional renal blood flow in ewes.

Regional blood flow to the kidneys was measured in 6 ewes by injecting carbonized microspheres (15 micrometer +/- 5) labeled with 85Sr into the left ventricle. There was no significant (P greater than 0.25) difference in the mean arterial pressure before and after injection of the microspheres. Normal values of blood flow to the outer cortex, inner cortex, and medulla were determined. The blood flow to the outer cortex was highest, followed (in a decreasing order) by the inner cortex and the medulla. Significant differences in blood flow were not detected between dogs, and sheep. The microsphere technique, based on Fick's principle, requires minimum instrumentation and does not require surgical manipulation of the kidney. The objective of the present experiment was to determine and compare the blood flow to regions of the ovine kidneys.

Animals↗
PubMed1981

Regional blood flow to the stomach and small intestine in swine.

The radioactive microsphere technique was used to measure regional blood flow to the stomach and small intestine of pigs weighing 20 to 37 kg. Mean regional blood flow (ml/min/100 g of tissue) was least in the nonglandular region, followed in an increasing order by the pyloric gland, cardiac gland, and proper gastric (fundic) gland regions. The region of the proper gastric glands accounted for 47.5% of the total gastric blood flow, with 24.9%, 23.8%, and 3.7% of the total flow going to the cardiac gland, pyloric gland, and nonglandular regions, respectively. Although there appeared to be a blood flow gradient in the small intestine, no significant difference in blood flow between the duodenum, jejunum, and ileum was observed. Mean blood flow to the small intestine was significantly greater than that to the stomach.

Animals↗
PubMed1980

Effect of prednisone on gastric blood flow in swine.

The effect of long-term prednisone treatment on gastric blood flow, as it relates to the development of gastric lesions, was studied. Young pigs were given (IM) saline solution or prednisone (10 mg/kg) each day for various periods. Blood flow was measured, using the radioactive microsphere entrapment technique, at the end of 7, 14, and 21 days of treatment. Pigs treated with prednisone had hemorrhages in the proper gastric (fundic) gland area of the stomach. Blood flow to the mucosa and total wall of the nonglandular, cardiac gland, fundic gland, and pyloric gland regions of the stomach was higher in prednisone-treated pigs. Gastric lesions were not observed in the saline-treated pigs. Regional blood flow to the gastric mucosa increased during the formation of prednisone-induced gastric lesions in swine.

Animals↗
PubMed1977

Regional blood flow to the stomach and small intestine in ponies.

Studies on regional blood flow to the stomach and small intestine were performed in 9 anesthetized ponies. Carbonized microspheres (15 +/- 5 micron in diameter) labeled with 85Sr were injected into the left atrium to determine blood flow distribution. In 4 ponies, the regional flows to mucosal-submucosal layers of the stomach and the small intestine were also measured. The nonglandular region of the stomach received the least blood per 100 g of tissue, and the duodenum received the greatest. The regional blood flow to the duodenum was significantly higher than that to the glandular stomach region, jejunum, and ileum.

Animals↗
PubMed1976

Regional coronary blood flow in ponies.

Regional coronary blood flow was measured by injecting radioactive microspheres (15 mum +/- 5 in diameter) into the left atrium of anesthetized ponies with surgically prepared open thorax before and during occlusion of the coronary arteries. The normal blood flow to the myocardium of the interventricular septum and the left ventricular wall were highest, followed in decreasing order by the right ventricular wall, the interatrial septum, the atrial walls, and the valves. Measurement of transmural blood flow in the normal left ventricle yielded a mean endocardial/epicardial flow ratio of 1.36 in the free wall. The left ventricular flow ratio was 1.33 in the septal wall. The percentage of the left ventricular myocardium made ischemic during occlusion of the right coronary artery or of the left coronary artery (cranial descending and circumflex arteries) was approximately equal. Blood flow to the ischemic areas of the left ventricle after occlusion of coronary arteries ranged from 3.8 to 20.6% of the normal flow. A disproportionate decrease in flow to the endocardial regions of the left ventricle was also observed in ischemic areas (mean inner/outer left ventricular wall flow ratio was 68.89% of the normal flow ratio).

Animals↗
PubMedDate not supplied

Coerulospinal cells containing neuropeptide Y in the cat.

Spinally projecting neuropeptide Y (NPY)-immunoreactive cells were sought in the feline locus coeruleus (LC) nuclear complex after horseradish peroxidase (HRP) injection into the lumbar cord; HRP injection was followed by intracerebroventricular colchicine administration. Our results revealed that a significant number (approximately 20% of all descending cells from the LC complex) of spinally projecting NPY-immunoreactive neurons arise from the LC alpha, the subcoeruleus and the Kölliker-Fuse nuclei. Other nonspinally projecting NPY-containing cells were also evident in the laterodorsal tegmental nucleus and the LCd, in addition to those occurring in the aforementioned LC nuclear complex.

Animals↗
PubMedDate not supplied

Immunohistochemical evidence for coexistence of methionine-enkephalin and tyrosine hydroxylase in neurons of the locus coeruleus complex projecting to the spinal cord of the cat.

Previous studies have revealed the presence of pontospinal neurons with either methionine-enkephalin- or tyrosine hydroxylase-like immunoreactivity in the dorsolateral pontine tegmentum of the cat. Using a combined fast blue retrograde transport technique and simultaneous immunofluorescence histochemistry, the present study was designed to reveal the coexistence of enkephalin and tyrosine hydroxylase in cat coerulospinal neurons and to determine if and to what extent the coerulospinal pathway is heterogeneous. Fast blue-labelled neurons with tyrosine hydroxylase- and enkephalin-like immunoreactivities were found in the nucleus locus coeruleus, nucleus subcoeruleus, Kölliker-Fuse nucleus, and the medial and lateral parabrachial nuclei. Approximately 87% of tyrosine hydroxylase-like immunoreactive neurons had enkephalin-like immunoreactivity, whereas about 76% of the enkephalin-like immunoreactive neurons had tyrosine hydroxylase-like immunoreactivity. About 71% of all coerulospinal neurons exhibited both tyrosine hydroxylase- and enkephalin-like immunoreactivities. These findings indicate that coerulospinal activity may lead to spinal cord effects reflecting both norepinephrine and enkephalin activity in most cases but do not rule out each transmitter's isolated functions.

Amidines↗
PubMedDate not supplied

Acute reversible left ventricular dysfunction following general anesthesia.

Acute reversible left ventricular dysfunction due to myocardial stunning is a known phenomenon during acute myocardial infarction, coronary angiography, coronary angioplasty or after coronary artery bypass surgery. We report a rare case of acute reversible dysfunction of the myocardium as a complication of general anesthesia in a patient with normal coronary arteries. This is a potentially fatal complication unless recognized early and treated aggressively.

Acute Disease↗