Heat stress induces ultrastructural changes in cutaneous capillary wall of heat-acclimated rock pigeon

1999 ◽  
Vol 277 (4) ◽  
pp. R967-R974 ◽  
Author(s):  
Yehuda Arieli ◽  
Neomi Feinstein ◽  
Pnina Raber ◽  
Michal Horowitz ◽  
Jacob Marder
Keyword(s):  
Heat Stress ◽  
Heat Exposure ◽  
Ultrastructural Changes ◽  
Water Evaporation ◽  
Adrenergic Agonist ◽  
Hot Environment ◽  
Adrenergic Antagonist ◽  
Cooling Mechanism ◽  
Cutaneous Evaporation ◽  
Endothelial Gaps

In heat-acclimated rock pigeons, cutaneous water evaporation is the major cooling mechanism when exposed at rest to an extremely hot environment of 50–60°C. This evaporative pathway is also activated in room temperature by a β-adrenergic antagonist (propranolol) or an α-adrenergic agonist (clonidine) and inhibited by a β-adrenergic agonist (isoproterenol). In contrast, neither heat exposure nor drug administration activates cutaneous evaporation in cold-acclimated pigeons. To elucidate the mechanisms underlying this phenomenon, we studied the role of the ultrastructure and permeability of the cutaneous vasculature. During both heat stress and the administration of propranolol and clonidine, we observed increased capillary fenestration and endothelial gaps. Similarly, propranolol increased the extravasation of Evans blue-labeled albumin in the skin tissue. We concluded that heat acclimation reinforces a mechanism by which the activation of adrenergic signal transduction pathways alters microvessel permeability during heat stress. Consequently the flux of plasma proteins and water into the interstitial space is accelerated, providing an interstitial source of water for sustained cutaneous evaporative cooling.

scholarly journals Heat Stress and Goat Welfare: Adaptation and Production Considerations

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1021
Author(s):  
Veerasamy Sejian ◽  
Mullakkalparambil V. Silpa ◽  
Mini R. Reshma Nair ◽  
Chinnasamy Devaraj ◽  
Govindan Krishnan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Condition Score ◽  
Heat Exposure ◽  
Stocking Density ◽  
Production Performance ◽  
Farm Animals ◽  
Meat Production ◽  
Important Species ◽  
Tropical Regions ◽  
Tropical Climates

This review attempted to collate and synthesize information on goat welfare and production constraints during heat stress exposure. Among the farm animals, goats arguably are considered the best-suited animals to survive in tropical climates. Heat stress was found to negatively influence growth, milk and meat production and compromised the immune response, thereby significantly reducing goats’ welfare under extensive conditions and transportation. Although considered extremely adapted to tropical climates, their production can be compromised to cope with heat stress. Therefore, information on goat adaptation and production performance during heat exposure could help assess their welfare. Such information would be valuable as the farming communities are often struggling in their efforts to assess animal welfare, especially in tropical regions. Broadly three aspects must be considered to ensure appropriate welfare in goats, and these include (i) housing and environment; (ii) breeding and genetics and (iii) handling and transport. Apart from these, there are a few other negative welfare factors in goat rearing, which differ across the production system being followed. Such negative practices are predominant in extensive systems and include nutritional stress, limited supply of good quality water, climatic extremes, parasitic infestation and lameness, culminating in low production, reproduction and high mortality rates. Broadly two types of methodologies are available to assess welfare in goats in these systems: (i) animal-based measures include behavioral measurements, health and production records and disease symptoms; (ii) resources based and management-based measures include stocking density, manpower, housing conditions and health plans. Goat welfare could be assessed based on several indicators covering behavioral, physical, physiological and productive responses. The important indicators of goat welfare include agonistic behavior, vocalization, skin temperature, body condition score (BCS), hair coat conditions, rectal temperature, respiration rate, heart rate, sweating, reduced growth, reduced milk production and reduced reproductive efficiency. There are also different approaches available by which the welfare of goats could be assessed, such as naturalistic, functional and subjective approaches. Thus, assessing welfare in goats at every production stage is a prerequisite for ensuring appropriate production in this all-important species to guarantee optimum returns to the marginal and subsistence farmers.

PSIII-11 Evaluating the Performance of Grow-finish Pigs Supplemented with Butipearl® Z and Kemtrace® Chromium During Natural Heat Stress Exposure

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 174-174
Author(s):  
Mark Knauer ◽  
Venkatesh Mani ◽  
Tom Marsteller ◽  
Vanessa Iseri ◽  
Brian Kremer
Keyword(s):  
Heat Stress ◽  
Feed Intake ◽  
Heat Exposure ◽  
Muscle Growth ◽  
Negative Control ◽  
Intestinal Damage ◽  
Intestinal Health ◽  
Negative Effects ◽  
Curvilinear Relationships ◽  
The Impact

Abstract Heat stress (HS) severely impacts swine leading to compromised barrier integrity, diminished intestinal health and decreased performance. ButiPEARL® Z (BPZ) is an encapsulated formulation of zinc and butyrate shown to alleviate the impact of HS by improving intestinal health. KemTRACE® Chromium (KTCr) is an organic trace mineral shown to decrease the impact of stress and improve glucose utilization, leading to muscle growth and improved performance. To test the efficacy of BPZ and KTCr on mitigating stress from natural heat exposure, a grow-finish trial was conducted from June-September. There were four treatments: negative control (NC), NC+.45kg BPZ, NC+.91kg BPZ and NC+1.82kg BPZ. Three BPZ treatments were also supplemented with 200ppb KTCr. Pigs (n=480) were randomly assigned to 96 pens at 22.5kg. Performance was measured at d0, 28, 56 and at marketing. From d56 to market, ADFI was greater (P< 0.05) for 0.45kg and 0.91kg BPZ when compared to NC and 1.82kg BPZ (3.40 and 3.35 vs. 3.26 and 3.27kg, respectively). Therefore, relationships between ADFI day 56 to market and ADFI day 0 to market with BPZ level were curvilinear (P< 0.05). Both market weight and overall ADG tended (P< 0.10) to have curvilinear relationships with BPZ level. While not different, 0.45kg and .91kg BPZ supplemented pigs were .97kg and 1.25kg heavier, respectively, on marketing day compared to control. No differences (P >0.10) were observed for Feed:Gain. Part of the negative effects of HS include decrease in feed intake which contributes to intestinal damage and decreased performance. Data from this study show that both treatment combinations were able to improve feed intake and decrease stress which might have led to the improved weight gain at the end. The data provides evidence that the combination of BPZ and KTCr may alleviate the negative effects of HS and help with the performance of grow-finish pigs during heat stress.

Effects of endogenous and exogenous catecholamines on LPS-induced neutrophil trafficking and activation

1999 ◽  
Vol 276 (1) ◽  
pp. L1-L8 ◽  
Author(s):  
Edward Abraham ◽  
Debra J. Kaneko ◽  
Robert Shenkar
Keyword(s):  
Systemic Circulation ◽  
Mrna Levels ◽  
Adrenergic Stimulation ◽  
Neutrophil Accumulation ◽  
Adrenergic Agonist ◽  
Nitric Oxide Synthase Inhibitor ◽  
Adrenergic Agents ◽  
Adrenergic Antagonist ◽  
Tnf Α ◽  
Synthase Inhibitor

Endotoxemia produces elevations in catecholamine levels in the pulmonary and systemic circulation as well as rapid increases in neutrophil number and proinflammatory cytokine expression in the lungs. In the present experiments, we examined the effects of endogenous and exogenous adrenergic stimulation on endotoxin-induced lung neutrophil accumulation and activation. Levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and macrophage inflammatory protein (MIP)-2 mRNAs were increased in lung neutrophils from endotoxemic mice compared with those present in lung neutrophils from control mice or in peripheral blood neutrophils from endotoxemic or control mice. Treatment with the β-adrenergic antagonist propranolol before endotoxin administration did not affect trafficking of neutrophils to the lungs or the expression of IL-1β, TNF-α, or MIP-2 by lung neutrophils. Administration of the α-adrenergic antagonist phentolamine before endotoxemia did not alter lung neutrophil accumulation as measured by myeloperoxidase (MPO) levels but did result in significant increases in IL-1β, TNF-α, and MIP-2 mRNA expression by lung neutrophils compared with endotoxemia alone. Administration of the α1-adrenergic agonist phenylephrine before endotoxin did not affect trafficking of neutrophils to the lungs but was associated with significantly increased expression of TNF-α and MIP-2 mRNAs by lung neutrophils compared with that found after endotoxin alone. In contrast, treatment with the α2-adrenergic agonist UK-14304 prevented endotoxin-induced increases in lung MPO and lung neutrophil cytokine mRNA levels. The suppressive effects of UK-14304 on endotoxin-induced increases in lung MPO were not affected by administration of the nitric oxide synthase inhibitor N-nitro-l-arginine methyl ester. These data demonstrate that the initial accumulation and activation of neutrophils in the lungs after endotoxemia can be significantly diminished by α2-adrenergic stimulation. Therapy with α2-adrenergic agents may have a role in modulating inflammatory pulmonary processes associated with sepsis-induced acute lung injury.

scholarly journals Geongangbuja-Tang Decoction and Its Active Ingredient, Aconiti Lateralis Radix Preparata, Exerts Inhibitory Effects on Heat Stress-Induced Inflammation in Mice

2021 ◽  
Vol 11 (15) ◽  
pp. 6902
Author(s):  
Eugene Huh ◽  
Wonil Lee ◽  
Yujin Choi ◽  
Tae Hee Lee ◽  
Myung Sook Oh
Keyword(s):  
Heat Stress ◽  
Energy Metabolism ◽  
Inflammatory Cytokines ◽  
Hpa Axis ◽  
Inflammatory Responses ◽  
Heat Exposure ◽  
Mouse Serum ◽  
Dependent Manner ◽  
Active Constituent ◽  
Pro Inflammatory Cytokines

Heat stress induces the hypothalamic-pituitary-adrenal (HPA) axis activation, influences biological responses, and reduces energy metabolism. Geongangbuja-tang (GBT) and its components, Zingiberis Rhizoma (ZOR) and Aconiti Lateralis Radix Preparata (ALRP) have been used to induce energy metabolism; however, the effects of GBT and its ingredients on heat-induced inflammatory responses have not yet been investigated. In this study, we performed an open-field test to evaluate locomotor activity in mice. To assess the effects of GBT and its ingredients on inflammation, the protein levels of c-fos, pro-inflammatory cytokines, and cortisol were measured in the mouse hypothalamus and serum. The results showed that GBT alleviated locomotive activity and reduced c-fos levels in a dose-dependent manner under the heat exposure. After investigating the active constituent of GBT, we found that compared to GBT and ZOR, ALRP significantly suppressed c-fos expression under heat stress. Subsequently, ALRP decreased the expression of pro-inflammatory cytokines, such as interleukin-9 and -13 and prostaglandin, under the heat stress in the mouse hypothalamus. Moreover, treatment with ALRP inhibited cortisol secretion in the mouse serum following heat exposure. These results indicate that GBT and its active component, ALRP, could be the thermoregulatory agents that regulate the HPA axis.

Blood gas changes during panting in a small East African antelope, the dik-dik

1978 ◽  
Vol 44 (4) ◽  
pp. 534-537 ◽  
Author(s):  
M. Maskrey ◽  
P. P. Hoppe ◽  
O. S. Bamford
Keyword(s):  
Heat Stress ◽  
Heat Exposure ◽  
Blood Gases ◽  
Respiratory Alkalosis ◽  
Second Phase ◽  
Blood Gas ◽  
Climatic Chamber ◽  
East African ◽  
Blood Samples ◽  
Arterial Blood

Five adult male dik-dik (Madoqua kirkii) were exposed in a climatic chamber to an air temperature of 45 degrees C. Measurements were made of rectal temperature (Tre) and respiratory frequency (f) and arterial blood samples taken before and during heat exposure were analyzed for pH, PCO2 and PO2. During exposure, Tre and f increased in all animals. In the first 80 min dik-dik displayed thermal tachypnea and minor changes in blood gases. Continued exposure lead to hyperpnea accompanied by a fall in PaCO2 and a rise in pH. PaCO2 at first fell and then increased toward or above control levels. The dik-dik did not display second phase breathing. This observation confirms that second phase breathing is not essential to the development of respiratory alkalosis. The main conclusion of the study is that the dik-dik, unlike another heat-adapted antelope, the wildebeest (Taylor, Robertshaw, and Hoffmann. Am. J. Physiol. 217:907–910, 1969), is unable to resist alkalosis during heat stress.

Dual α2-Adrenergic Agonist and α1-Adrenergic Antagonist Actions of Dexmedetomidine on Human Isolated Endothelium-Denuded Gastroepiploic Arteries

2002 ◽  
Vol 94 (6) ◽  
pp. 1434-1440 ◽  
Author(s):  
Junichirou Hamasaki ◽  
Isao Tsuneyoshi ◽  
Rumi Katai ◽  
Tatewaki Hidaka ◽  
Walter A. Boyle ◽  
...  
Keyword(s):  
Adrenergic Agonist ◽  
Adrenergic Antagonist

The β3-adrenergic agonist (BRL35135A) acutely increases oxygen consumption and plasma intermediate metabolites in sheep

2011 ◽  
Vol 51 (10) ◽  
pp. 881 ◽  
Author(s):  
Samadi ◽  
M. Jois ◽  
F. R. Dunshea ◽  
B. J. Leury
Keyword(s):  
Fatty Acids ◽  
Oral Dose ◽  
Treatment Time ◽  
Co2 Production ◽  
Receptor Subtypes ◽  
Adrenergic Agonist ◽  
Esterified Fatty Acids ◽  
Adrenergic Antagonist ◽  
Intermediate Metabolites ◽  
Plasma Metabolite

There is evidence that an atypical adrenoreceptor subtype is involved in mediating some of the physiological effects of catecholamines, particularly in some adipose tissue sites. Therefore, three experiments were conducted to determine the metabolic and energetic responses to oral administration of the purported β3-agonist BRL35135A in ruminant lambs. The post-prandial increase in O2 consumption (0.109 versus 0.139 L/min) and CO2 production (0.102 versus 0.127 L/min) at 30 min after feeding was greater (P < 0.05) in the lambs receiving 5 mg of the BRL35135A. Treatment × time interactions over the period between –50 and 220 min indicate significant increases in plasma non-esterified fatty acids (P < 0.001), glucose (P < 0.001) and lactate (P = 0.024) in lambs consuming a single oral dose of 5 mg BRL35135A. In a subsequent experiment there were similar interactions over the period between –120 and 1440 min for non-esterified fatty acids (P < 0.001), glucose (P < 0.001) and lactate (P < 0.001) in lambs consuming a lower oral dose of 1 mg BRL35135A. The effects of BRL35135A on plasma non-esterified fatty acids (P = 0.95), glucose (P = 0.84) and lactate (P = 0.68) were not modified by the β1- and β2-adrenergic antagonist alprenolol suggesting that the effects were mediated via β3-adrenergic receptor subtypes. In conclusion, these experiments indicate that BRL35135A is acutely active in sheep when given with feed, as indicated by increases in respiratory gas exchange and plasma metabolite concentrations.

Calcium and alpha-adrenergic regulation of Na-Cl(K) cotransport in rabbit tracheal epithelial cells

1990 ◽  
Vol 259 (2) ◽  
pp. L66-L72
Author(s):  
C. M. Liedtke
Keyword(s):  
Epithelial Cells ◽  
Initial Rate ◽  
Critical Role ◽  
Loop Diuretics ◽  
Base Line ◽  
Tracer Transport ◽  
Adrenergic Agonist ◽  
Adrenergic Agents ◽  
Cl Transport ◽  
Adrenergic Antagonist

The marked sensitivity of Cl and fluid secretion in mammalian airways to basolateral application of loop diuretics has led to postulates that electrically neutral Na-Cl entry plays a critical role during secretion. Electrically neutral Na-Cl(K) cotransport was investigated by determining the initial rate of 22Na and 36Cl efflux in epithelial cells isolated from rabbit trachea and preequilibrated with radioactive tracer at 25 degrees C. Tracer transport was initiated by 10-fold dilution of an aliquot of cells in radioisotope-free medium. The initial rate of radiolabeled ion transport was calculated from the linear portion of efflux curves. Base-line Na and Cl transport rates were not affected by furosemide or bumetanide. l-Epinephrine stimulated Na and Cl transport rates 1.8-fold each in Ca2(+)-replete and 2.6- and 2.3-fold, respectively, in Ca2(+)-deficient transport medium. Loop diuretics and yohimbine, an alpha 2-adrenergic antagonist, blocked the effects of l-epinephrine, and, clonidine, an alpha 2-adrenergic agonist, stimulated yohimbine- and furosemide-sensitive Cl transport. The beta-adrenergic agonist l-isoproterenol alone did not affect tracer transport and, in combination with clonidine, did not affect the response to clonidine. Elevation of intracellular Ca2+ with ionomycin stimulated tracer transport, and buffering of intracellular Ca2+ with 1,2-bis(aminophenoxy)ethane- N,N,N',N'-tetraacetic acid blocked the stimulatory effects of alpha-adrenergic agents. These results indicate an alpha 2-adrenergic stimulation of loop diuretic-sensitive Na and Cl transport that requires elevated intracellular Ca2+ as the second messenger. The transport mechanism is probably a Na-Cl or Na-K-2Cl cotransport located in the basolateral membrane.

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