• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.5
• /
• pp.427-434
• /
• 2015

Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

• Korean Journal of Agricultural Science
• /
• v.47 no.3
• /
• pp.683-691
• /
• 2020

A biomarker is needed to monitor and manage the health of pigs from heat stress (HS). Therefore, we investigated the effects of HS on growth performance, nutrient digestibility, and blood profiles in finishing pigs. A total of 12 finishing pigs (n = 12) were raised in thermal neutral (TN; 25℃) conditions for a 3-d adaptation period. After the adaption, 6 pigs were exposed to HS at 33℃ (HS33) for 5 d. The pigs were fed the same diet based on corn and soybean meal. Chromic oxide was added to all the diets at a level of 2 g·kg^-1 as an indigestible marker for the determination of the apparent total track digestibility (ATTD) of nutrients and amino acids. Blood samples were collected after the adaptation and heat treatment to verify the blood profiles. The HS33 pigs had a lower (p < 0.01) average daily feed intake (ADFI) and higher (p < 0.05) rectal temperature compared to the TN pigs. However, there was no difference in the ATTD of nutrients and amino acids. The HS33 pigs had reduced (p < 0.05) levels of serum glucose, non-esterified fatty acids (NEFA), total protein, albumin, and calcium compared to the TN pigs. However, the level of total bilirubin was increased (p < 0.05) in the HS pigs. In conclusion, HS reduced the feed intake and had an adverse effect on health. Altered blood profiles as a result of a negative energy balance are expected to be biomarkers of HS in finishing pigs.

• The Korean Journal of Physiology
• /
• v.26 no.1
• /
• pp.37-44
• /
• 1992

The encapsulation of the Purified bovine hemoglobin with Phospholipids obtained from egg folk was performed using a rotary vacuum evaporator. The prepared Hb-containing liposome (hemosome) had good properties as artificial red blood cell. The shape and size of the hemosomes were measured by a phase contrast microscope and image analyzer. The function of the hemosome as oxygen carrier was tested by measuring oxygen saturation curve with blood gas analyzer and infusing it into rats. The prepared hemosome was 1.184 + 0.423 ${\mu}m$ in diameter and round in shape. $P_{50}$ value of the hemosome solution was 28 mmHg. The synthesized red cells seem to function as oxygen carrier, because the severely bled rats were prolonged in their life by transfusion of the hemosome solution containing bovine hemoglobin.

• The Korean Journal of Physiology
• /
• v.24 no.2
• /
• pp.261-268
• /
• 1990

It has long been suggested that the cardiac atrium is a low pressure volume receptor controlling body fluid volume and blood pressure. Recently, the cardiac atrium has been found to contain a family of powerful peptides. To clarify the relationship between high blood pressure and the biologically active atrial peptides, experiments were done to define the characteristics of atrial natriuretic peptide secretion in the isolated perfused atria of renal hypertensive rats. Higher concentrations of plasma atrial natriuretic peptide and renin activity were observed in the two-kidney, one clip hypertensive rat compared to the normotensive rat. Atrial volume changes in response to pressure elevations were attenuated in hypertensive rats compared to normotensive rats. Incremental response to atrial volume changes in ANP secretion was accentuated in hypertensive rats. These date suggest that the accentuated atrial natriuretic peptide response to volume changes of hypertensive rats may be a physiological or pathphysiological adaptation to the high blood pressure and may be, at least in part, responsible for the elevated levels of plasma atrial natriuretic peptide observed in hypertensive rats.

• The Korean Journal of Physiology
• /
• v.1 no.2
• /
• pp.181-184
• /
• 1967

Hypothalamus is one of the most important center regulating voluntary and involuntary function of the body. We studied on the blood glucose and eosinophilic responses induced by electrical hypothalamic stimulation using stereotaxic apparatus. Blood glucose was measured according to Somogyi Nelson method and circulating eosinophil was counted with Hinkleman Stain. For the histological confirmation of electrode placement frozen sections were cut along electrode tract and stained with Hematoxylin-Eosin. The results obtained were as follows: 1. Anterior hypothalamic stimulation mostly leads to hypoglycemia but in some cases lead to hyperglycemia. 2. Hypothalamic stimulation leads to eosinopenia in majority cases. 3. There is no relationship between eosinopenia and hyperglycemia. 4. It appears that sympathetic and pararympathetic areas are not separate part but it coincides each other.

• The Korea Journal of Herbology
• /
• v.32 no.1
• /
• pp.15-23
• /
• 2017

Objectives : It is well known that Sibjotang (Shizaotang), traditional herbal medicine formula, regulates the body fluid blood pressure homeostasis. This study is to investigate whether Sibjotang improves diabetic renal dysfunction in type II diabetes mellitus animal model, db/db mice. Methods : The animals model were divided into three groups at the age of 8 weeks; control group (C57BLKS/J-db/m mice), diabetic group [(C57BLKS/J+Lepr)-db/db mice], and Sibjotang group [(C57BLKS/J+Lepr)-db/db mice + Sibjotang 100 mg/kg/day]. During 8 weeks of treatment, blood glucose and urinary albumin excretion were checked in metabolic chamber at 8, 12, and 16 weeks of age, respectively. Results : Body weight and food intake of diabetic group were significantly higher than control group after 8 weeks administration. However, there were not significant different between the diabetic group and Sibjotang group. Urinary albumin excretion was significantly decreased in the Sibjotang group than the diabetic group. In addition, supplementation with Sibjotang significantly lowered levels of blood glucose, insulin, and homeostatic model assessment-insulin resistance (HOMA-IR), suggesting reduced insulin resistance. The ratio of mesangial matrix/glomerular area was markedly larger in diabetic group than control group, whereas Sibjotang significantly reduced this expansion. Moreover, immunohistological study revealed that Sibjotang attenuated the increase of transforming growth $factor(TGF)-{\beta}$ expression in kidney. Conclusion : Sibjotang ameliorates diabetes-associated renal injury through the improvement of the blood glucose and insulin sensitivity, and inhibiting the $TGF-{\beta}1$ expression. Therefore, Sibjotang may be a new therapeutic formula for the treatment of diabetic-associated renal dysfunction.

• The Korean Journal of Physiology
• /
• v.5 no.2
• /
• pp.1-7
• /
• 1971

The osmotic and mechanical red cell fragility of the professional blood donors, who were found to be anemic as the result of frequent and repeated blood loss the past 5-6 years, were compared with that of the normal person while incubating the blood at $4-6^{\circ}C$ for 28 days. The fragility was expressed as % hemolysis occured during the incubation, and the following results were obtained: 1. The osmotic fragility in the normal persons (i.e, ; control group) progressively increased as the incubation became longer, and % hemolysis in 0.42% NaCl solution at 0, 10, 15, 21 and 28 incubation day was 31.90, 50.20, 41.68, 43.50 and 55.40 respectively. The mechanical fragility. in the normal red cells ranged between the minimum of 0.00% to the maximum of 5.80% both in 0.90 and 0.66% of NaCl solutions. 2. The hemolysis curve obtained in the red cell osmotic fragility from three cases of the anemic persons (i.e,; experimental group) showed a significant left side shift comparing with the normal in general which indicates that the fragility was more increased in the experimental group. The mechanical fragility in the experimental group ranged between the minimum 0.00% to the maximum 19.00% both in 0.90 and 0.66% of NaCl solutions. 3. The red cells of the chronic anemic person due to the frequent blood loss as the professional blood donor exhibit significantly marked increase both in osmotic and mechanical fragility comparing with the normal, and the tendency was more prominent as the incubation period became longer.

• The Korean Journal of Physiology
• /
• v.30 no.1
• /
• pp.21-31
• /
• 1996

To investigate the mechanisms of increased endothelium-dependent contraction by acetylcholine in hypertensive rats, the relationship between endothelium-dependent contraction by acetylcholine and blood pressure was studied in spontaneously hypertensive rats (SHR), one-kidney, one clip Goldblatt hypertension (1K,1C-GBH) rats, and Wistar-Kyoto rats (WKY). SHR were treated orally with enalapril or nicardipine in order to prevent development of hypertension or suppress the developed hypertension. 1K,1C-GBH rats were made by renal artery stenosis with contralateral nephrectomy in 8 week-WKY. 1. Endothelium-dependent contractions by acetylcholine $(10^{-6}{\sim}10^{-5}\;M)$ in SHR were significantly greater than those in WKY. 2. Chronic treatment with enalapril or nicardipine reduced the endothelium-dependent contraction in SHR 3. The degree of reduction of endothelium-dependent contraction was greater in SHR which was prevented from developing hypertension than in SHR of which high blood pressure was suppressed. 4. In aortic rings from 1K,1C-GBH rats, endothelium-dependent contractions by acetylcholine were augmented as compared with WKY. 5. There is good relationship between the value of blood pressure and magnitude of endothelium-dependent contraction. Thus, it is suggested that increased endothelium-dependent contraction in hypertensive rats may he due to the high blood pressure and endothelium-dependent contraction may not be a cause of the initiation of hypertension in SHR.

• The Korean Journal of Physiology and Pharmacology
• /
• v.27 no.5
• /
• pp.481-491
• /
• 2023

The β subunits of high voltage-gated calcium channels (HGCCs) are essential for optimal channel functions such as channel gating, activation-inactivation kinetics, and trafficking to the membrane. In this study, we report for the first time the potent blood pressure-reducing effects of peptide fragments derived from the β subunits in anesthetized and non-anesthetized rats. Intravenous administration of 16-mer peptide fragments derived from the interacting regions of the β1 [cacb1(344-359)], β2 [cacb2(392-407)], β3 [cacb3(292-307)], and β4 [cacb4(333-348)] subunits with the main α-subunit of HGCC decreased arterial blood pressure in a dose-dependent manner for 5-8 min in anesthetized rats. In contrast, the peptides had no effect on the peak amplitudes of voltage-activated Ca²⁺ current upon their intracellular application into the acutely isolated trigeminal ganglion neurons. Further, a single mutated peptide of cacb1(344-359)-cacb1(344-359)_K357R-showed consistent and potent effects and was crippled by a two-amino acid-truncation at the N-terminal or C-terminal end. By conjugating palmitic acid with the second amino acid (lysine) of cacb1(344-359)_K357R (named K2-palm), we extended the blood pressure reduction to several hours without losing potency. This prolonged effect on the arterial blood pressure was also observed in non-anesthetized rats. On the other hand, the intrathecal administration of acetylated and amidated cacb1(344-359)_K357R peptide did not change acute nociceptive responses induced by the intradermal formalin injection in the plantar surface of rat hindpaw. Overall, these findings will be useful for developing antihypertensives.

• The Korean Journal of Physiology
• /
• v.2 no.1
• /
• pp.17-21
• /
• 1968

Total body oxygen uptake was measured in rats following hemorrhage (16 rats) and blood transfusion (7 rats) under light Nembutal anesthesia. Arterial blood Pressure measured on the tail artery decreased or increased following hemorrhage or transfusion. No direct relationship was observed between arterial blood pressure alteration and oxygen intake variation. Hematocrit ratio which changed after hemorrhage or transfusion showed a direct relationship with oxygen intake. Decrease in hematocrit ratio resulted in a decrease in oxygen intake of rats. The correlation coefficient between decrement of hematocrit ratio and decrement of oxygen intake was r=.56. The correlation coefficient between increment of hematocrit ratio and increment of oxygen intake was r=.86. Thus it was concluded that alteration in oxygen intake was limited by the systemic oxygen transport capacity of blood.