Drugs and natural products for the treatment of COVID-19 during 2020, the first year of the pandemic.

This work aimed to show which treatments showed efficacy against coronavirus disease 2019 (COVID-19); therefore, the results of 37 clinical trials started in 2020 and completed in 2021 are reviewed and discussed here. These were selected from databases, excluding vaccines, computational studies, in silico, in vitro, and those with hyperimmune sera from recovered patients. We found 34 drugs, one vitamin, and one herbal remedy with pharmacological activity against symptomatic COVID-19. They reduced mortality, disease progression, or recovery time. For each treatment, the identifier and type of trial, the severity of the disease, the sponsor, the country where the trial was conducted, and the trial results are presented. The drugs were classified according to their mechanism of action. Several drugs that reduced mortality also reduced inflammation in the most severe cases. These include some that are not considered anti-inflammatory, such as Aviptadil, pyridostigmine bromide, anakinra, imatinib, baricitinib, and bevacizumab, as well as the combination of ivermectin, aspirin, dexamethasone, and enoxaparin. Nigella sativa seeds with honey have also been reported to have therapeutic activity. On the other hand, tofacitinib, novaferon with ritonavir, and lopinavir were also effective, as well as in combination with antiviral therapies such as danoprevir with ritonavir. The natural products colchicine and Vitamin D3 were only effective in patients with mild-to-moderate COVID-19, as was hydroxychloroquine. Drug repositioning has been the main tool in the search for effective therapies by expanding the pharmacological options available to patients.

El objetivo del presente trabajo fue conocer qué tratamientos mostraron efectividad contra COVID-19, para lo cual se revisan y discuten los resultados de 37 estudios clínicos iniciados durante 2020 y concluidos en 2021. Estos fueron seleccionados de bases de datos, excluyendo vacunas, estudios computacionales, in silico, in vitro y con sueros hiperinmunes de pacientes recuperados. Se documentaron 34 fármacos, una vitamina y un remedio herbolario, con actividad farmacológica ante COVID-19 sintomático. Estos redujeron la mortalidad, el progreso de la enfermedad, o el tiempo de recuperación. Para cada tratamiento se presenta identificador y tipo de estudio, la gravedad de la enfermedad, patrocinador, país donde se realizó, así como sus resultados. Los fármacos se clasificaron de acuerdo con su mecanismo de acción. Varios fármacos que redujeron la mortalidad también disminuyeron la inflamación en los casos más graves. Esto incluyendo algunos no considerados antiinflamatorios, como el aviptadil, el bromuro de piridostigmina, el anakinra, el imatinib, el baricitinib y el bevacizumab, así como la combinación de ivermectina, aspirina, dexametasona y enoxaparina. También se reportaron con actividad terapéutica las semillas de Nigella sativa con miel. Además, resultaron efectivos el tofacitinib, el novaferón con ritonavir y lopinavir, así como los antivirales en terapias combinadas como el danoprevir con ritonavir. Los productos naturales colchicina y vitamina D3, solo tuvieron actividad en los pacientes en estado leve a moderado de la COVID-19, así como la hidroxicloroquina. El reposicionamiento de fármacos fue la principal herramienta para buscar terapias efectivas ampliando las opciones farmacológicas accesibles a los pacientes.

Hutchinson-Gilford Progeria Syndrome: Cellular Mechanisms and Therapeutic Perspectives.

In humans, aging is characterized by a gradual decline of physical and psychological functions, with the concomitant onset of chronic-degenerative diseases, which ultimately lead to death. The study of Hutchinson-Gilford progeria syndrome (HGPS), a premature aging disorder that recapitulates several features of natural aging, has provided important insights into deciphering the aging process. The genetic origin of HGPS is a de novo point mutation in the LMNA gene that drives the synthesis of progerin, mutant version of lamin A. Progerin is aberrantly anchored to the nuclear envelope disrupting a plethora of molecular processes; nonetheless, how progerin exerts a cascade of deleterious alterations at the cellular and systemic levels is not fully understood. Over the past decade, the use of different cellular and animal models for HGPS has allowed the identification of the molecular mechanisms underlying HGPS, paving the way towards the development of therapeutic treatments against the disease. In this review, we present an updated overview of the biology of HGPS, including its clinical features, description of key cellular processes affected by progerin (nuclear morphology and function, nucleolar activity, mitochondrial function, protein nucleocytoplasmic trafficking and telomere homeostasis), as well as discussion of the therapeutic strategies under development.

Anti-Inflammatory Effects of Flavonoids in Common Neurological Disorders Associated with Aging.

Aging reduces homeostasis and contributes to increasing the risk of brain diseases and death. Some of the principal characteristics are chronic and low-grade inflammation, a general increase in the secretion of proinflammatory cytokines, and inflammatory markers. Aging-related diseases include focal ischemic stroke and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are the most common class of polyphenols and are abundantly found in plant-based foods and beverages. A small group of individual flavonoid molecules (e.g., quercetin, epigallocatechin-3-gallate, and myricetin) has been used to explore the anti-inflammatory effect in vitro studies and in animal models of focal ischemic stroke and AD and PD, and the results show that these molecules reduce the activated neuroglia and several proinflammatory cytokines, and also, inactivate inflammation and inflammasome-related transcription factors. However, the evidence from human studies has been limited. In this review article, we highlight the evidence that individual natural molecules can modulate neuroinflammation in diverse studies from in vitro to animal models to clinical studies of focal ischemic stroke and AD and PD, and we discuss future areas of research that can help researchers to develop new therapeutic agents.

Sperm Dysfunction in the Testes and Epididymides due to Overweight and Obesity Is Not Caused by Oxidative Stress.

Obesity is a condition that has been linked to male infertility. The current hypothesis regarding the cause of infertility is that sperm are highly sensitive to reactive oxygen species (ROS) during spermatogenesis in the testes and transit through the epididymides, so the increase in ROS brought on by obesity could cause oxidative stress. The aim of this study was to evaluate whether the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) is capable of counteracting oxidative stress in sperm. The male Wistar rat was used as an overweight and obesity model, and analysis of fertility in these groups was carried out including the control group. Serum testosterone levels were determined, and the scrotal fat, testes, and epididymides were extracted. The epididymides were separated ini0 3 principal parts (caput, corpus, and cauda) before evaluating sperm viability, sperm morphology, damage to desoxyribonucleic acid of the sperm, and ROS production. The protein content and specific activity of the three enzymes mentioned above were evaluated. Results showed a gain in body weight and scrotal fat in the overweight and obese groups with decreased parameters for serum testosterone levels and sperm viability and morphology. Fertility was not greatly affected and no DNA integrity damage was found, although ROS in the epididymal sperm increased markedly and Raman spectroscopy showed a disulfide bridge collapse associated with DNA. The specific activities of CAT and GPX increased in the overweight and obesity groups, but those of SOD did not change. The amounts of proteins in the testes and epididymides decreased. These findings confirm that overweight and obesity decrease concentrations of free testosterone and seem to decrease protein content, causing poor sperm quality. Implications. An increase in scrotal fat in these conditions fosters an increase of ROS, but the increase of GPX and CAT activity seems to avoid oxidative stress increase in the sperm without damaging your DNA.

Diet-Induced Metabolic Dysfunction of Hypothalamic Nutrient Sensing in Rodents.

A sedentary lifestyle and excessive nutrient intake resulting from the consumption of high-fat and calorie-rich diets are environmental factors contributing to the rapid growth of the current pandemic of type 2 diabetes mellitus (DM2). Fasting hyperglycemia, an established hallmark of DM2, is caused by excessive production of glucose by the liver, resulting in the inability of insulin to suppress endogenous glucose production. To prevent inappropriate elevations of circulating glucose resulting from changes in nutrient availability, mammals rely on complex mechanisms for continuously detecting these changes and to respond to them with metabolic adaptations designed to modulate glucose output. The mediobasal hypothalamus (MBH) is the key center where nutritional cues are detected and appropriate modulatory responses are integrated. However, certain environmental factors may have a negative impact on these adaptive responses. For example, consumption of a diet enriched in saturated fat in rodents resulted in the development of a metabolic defect that attenuated these nutrient sensing mechanisms, rendering the animals prone to developing hyperglycemia. Thus, high-fat feeding leads to a state of "metabolic disability" in which animals' glucoregulatory responses fail. We postulate that the chronic faltering of the hypothalamic glucoregulatory mechanisms contributes to the development of metabolic disease.

Effect of Chronic Moderate Caloric Restriction on the Reproductive Function in Aged Male Wistar Rats.

Caloric restriction (CR) has been shown to be an effective nutritional intervention for increasing longevity in some animal species. The objective of this study was to evaluate CR's effects on metabolic and reproductive parameters in 12-month-old male Wistar rats. The rats were distributed in three groups: control, CR at 15%, and CR at 35% for 6 (up to 18 months of age) and 12 months (up to 24 months of age). At the end of CR treatment, we evaluated reproductive (male sexual behavior (MSB), sperm quality) and biochemical parameters (plasma glucose, glucose-regulating hormone, and sex steroid levels), and quantified annexin V in the seminiferous epithelium. Results showed that MSB and sperm quality were improved after 6 months of CR associated with increases in plasma testosterone and decrease annexin V in the seminiferous epithelium of the testicles compared to their control group. The metabolic profile of the CR rats also improved compared to controls. However, these effects of CR on reproductive parameters were not maintained after 12 months of CR. Findings suggest that beginning CR at the age of maturity reestablishes the behavioral sexual response and reproductive function in older animals after 6 months of CR and improves endocrine functioning during aging.

Comparison of body fat percentage assessments by bioelectrical impedance analysis, anthropometrical prediction equations, and dual-energy X-ray absorptiometry in older women.

Background: Individuals with high body fat have a higher risk of mortality. Numerous anthropometric-based predictive equations are available for body composition assessments; furthermore, bioelectrical impedance analysis (BIA) estimates are available. However, in older adults, the validity of body fat estimates requires further investigation. Objective: To assess the agreement between percentage body fat (BF%) estimates by BIA and five predictive equations based on anthropometric characteristics using dual X-ray absorptiometry (DXA) as reference method. A secondary objective was to identify whether excluding short-stature women improves the agreement of BF% estimates in a group of community-dwelling, older Mexican women. Methods: A concordance analysis of BF% was performed. A total of 121 older women participated in the study. Anthropometric information, BIA, and DXA body composition estimates were obtained. Five equations using anthropometric data were evaluated in order to determine body fat percentage (BF%) using DXA as reference method. Paired t-test comparisons and standard error of estimates (SEE) were obtained. The Bland-Altman plot with 95% limits of agreement and the concordance correlation coefficient (CCC) were used to evaluate the BF% prediction equations and BIA estimates. Results: The mean age of the study participants was 73.7 (±5.8) years old. BIA and the anthropometric based equations examined showed mean significant differences when tested in the entire sample. For the taller women (height > 145 cm), no significant difference in the paired comparison was found between DXA and BIA of BF% estimates. The mean BF% was 40.3 (±4.8) and 40.7 (±6.2) for DXA and BIA, respectively. The concordance between methods was good (CCC 0.814), (SEE 2.62). Also, in the taller women subset, the Woolcott equation using waist-to-height ratio presented no significant difference in the paired comparison; however, the error of the estimates was high (SEE 3.37) and the concordance was moderate (CCC 0.693). Conclusion: This study found that BIA yielded good results in the estimation of BF% among women with heights over 145 cm. Also, in this group, the Woolcott predictive equation based on waist circumference and height ratio showed no significant differences compared to DXA in the paired comparison; however, the large error of estimates observed may limit its application. In older women, short stature may impact the validity of the body fat percentage estimates of anthropometric-based predictive equations.

Immune system modulation in aging: Molecular mechanisms and therapeutic targets.

The function of the immune system declines during aging, compromising its response against pathogens, a phenomenon termed as "immunosenescence." Alterations of the immune system undergone by aged individuals include thymic involution, defective memory T cells, impaired activation of naïve T cells, and weak memory response. Age-linked alterations of the innate immunity comprise perturbed chemotactic, phagocytic, and natural killing functions, as well as impaired antigen presentation. Overall, these alterations result in chronic low-grade inflammation (inflammaging) that negatively impacts health of elderly people. In this review, we address the most relevant molecules and mechanisms that regulate the relationship between immunosenescence and inflammaging and provide an updated description of the therapeutic strategies aimed to improve immunity in aged individuals.

Vitamin D Deficiency is Associated with Handgrip Strength, Nutritional Status and T2DM in Community-Dwelling Older Mexican Women: A Cross-Sectional Study.

The aim of this study was to evaluate the association between handgrip strength, nutritional status and vitamin D deficiency in Mexican community-dwelling older women. A cross sectional study in women ≥ 60 years-old was performed. Plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured by a quantitative immunoassay technique. Handgrip strength was assessed using a dynamometer, while nutritional status was assessed through the Full Mini Nutritional Assessment (Full-MNA). A total of 116 women participated in the study, their mean age was 70.3 ± 5.8 years; 49.1% of the study group had plasma 25(OH)D levels lower than 40 nmol/L [16 ng/mL]. Meanwhile, 28.45% of participants had low handgrip strength (<16 kg), and 23.1% were identified at risk of malnutrition/malnourished according with Full-MNA score. Women with 25(OH)D deficiency (<40 nmol/L [16 ng/mL]) were more likely to have low handgrip strength (OR = 2.64, p = 0.025) compared with those with higher 25(OH)D values. Additionally, being malnourished or at risk of malnutrition (OR = 2.53, p = 0.045) or having type 2 diabetes mellitus (T2DM) (OR = 2.92, p = 0.044) was also associated with low 25(OH)D. The prevalence of low plasma 25(OH)D concentrations was high among Mexican active older women. Low handgrip strength, being at risk of malnutrition/malnourished, or diagnosed with T2DM was also associated with Vitamin D deficiency.

Physiopathology of ischemic stroke and its modulation using memantine: evidence from preclinical stroke.

Ischemic stroke is the most common type of cerebrovascular disease and is caused by an interruption of blood flow in the brain. In this disease, two different damage areas are identifying: the lesion core, in which cells quickly die; and the penumbra (surrounding the lesion core), in which cells are functionally weakened but may recover and restore their functions. The currently approved treatments for ischemic stroke are the recombinant tissue plasminogen activator and endovascular thrombectomy, but they have a short therapeutic window (4.5 and 6 hours after stroke onset, respectively) and a low percentage of stroke patients actually receive these treatments. Memantine is an approved drug for the treatment of Alzheimer's disease. Memantine is a noncompetitive, low affinity and use-dependent antagonist of N-methyl-D-aspartate glutamate receptor. Memantine has several advantages over developing a new drug to treat focal ischemic stroke, but the most important is that it has sufficient safe probes in preclinical models and humans, and if the preclinical studies provide more evidence about pharmacological actions in tissue protection and repair, this could help to increase the number of clinical trials. The present review summarizes the physiopathology of isquemic stroke and the pharmacological actions in neuroprotection and neuroplasticity of memantine in the post stroke stage of preclinical stroke models, to illustrate their potential to improve functional recovery in human patients.

Unraveling the Role of Discrete Areas of the Rat Brain in the Regulation of Ovulation through Reversible Inactivation by Tetrodotoxin Microinjections.

Many experimental approaches have been used for studying the role of the brain in the regulation of ovulation. Examples include the lesion and deafferentation of neuronal groups, which are both invasive methods that permanently impair the integrity of the target area. These methods are accompanied by collateral effects that can affect the analysis of acute and temporal regulatory mechanisms. The stereotaxic implantation of guide cannulas aimed at specific brain regions, followed by a recovery period, allows researchers to microinject different drugs after the disappearance of the undesired effects of the surgery. Tetrodotoxin has been used to determine the roles of several brain areas in diverse physiological processes because it transiently inhibits the sodium-dependent action potentials, thus blocking all neural activity in the target region. This protocol combines this method with strategies for the assessment of the estrous cycle and ovulation to reveal the role of discrete brain regions in the regulation of ovulation at particular times of any given stage of the estrous cycle. Awake and unrestrained rats (Rattus norvegicus) were used to avoid the blocking effects that anesthetics and stress hormones exert on ovulation. This protocol can be easily adapted to other species, brain targets and pharmacological agents to study different physiological processes. Future improvements to this method include the design of a microinjection system using glass capillaries of small diameter instead of guide cannulas. This will reduce the amount of tissue damaged during the implantation and decrease the spread of the infused drugs outside the target area.

Prevalence of Malnutrition and Depression in Older Adults Living in Nursing Homes in Mexico City.

This study evaluated the association between nutritional status, depressive symptoms, and the number of prescription drugs taken by older adults living in nursing homes in Mexico City. In a cross-sectional study, 262 participants were subjected to anthropometric and nutritional (Mini Nutritional Assessment (MNA)) evaluations; additionally, their depression (Geriatric Depression Scale (GDS)) and functional status were assessed. Multiple logistic regression was used for identifying factors associated with the risk of malnutrition/malnourishment. The mean age of participants was 83.1 ± 8.6 years. A total of 59.9% and 21.1% were at risk of malnutrition and malnourished, respectively. With respect to depression, 27.9% of the participants had mild depression, while 11.4% showed severe depression. An inverse correlation between MNA evaluations and depression scores was found (Spearman's ρ = -0.4624, p < 0.001); residents with a better nutritional status had lower depression scores. Individuals with depressive symptoms were approximately five times more likely to be at risk of malnutrition or malnourished (OR = 5.82, 95% CI = 2.27-14.89) than individuals without depression. Residents taking three or more prescription drugs daily (OR = 1.83, 95% CI = 1.27-2.63, p < 0.001) were more likely to be at risk of malnutrition or malnourished. In summary, poor nutritional status was associated with depression, while the intake of numerous prescription drugs was associated with being at risk of malnutrition or malnourished.

The content of gonadotropin-releasing hormone (GnRH), kisspeptin, and estrogen receptors (ERα/ERß) in the anteromedial hypothalamus displays daily variations throughout the rat estrous cycle.

The content of gonadotropin-releasing hormone (GnRH), its mRNA, and estrogen receptor alpha (ERα) and beta (ERß) in the hypothalamus varies throughout the estrous cycle. Furthermore, the abundance of these molecules displays asymmetry between the right and left side. In the present study, we investigated the changes in the content of ERα, ERß, kisspeptin, and GnRH by western blot in the left and right anteromedial hypothalamus, at four different times during each stage of the rat estrous cycle. The serum levels of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were also measured. ERα and ERß levels changed depending on the stage of the estrous cycle, meanwhile that of kisspeptin was modified according to both the hour of the day and the stage of the cycle. Except in estrus day, ERß was higher in the right hypothalamus, while ERα was similar in both sides. During both proestrus and estrus, the content of kisspeptin and GnRH was higher in the right hypothalamus. The highest levels of FSH and LH occurred at 17:00 h of proestrus. But at estrus, the highest FSH levels were observed at 08:00 h and the lowest at 17:00 h. Thus, the current results show that the content of ERα, ERß, kisspeptin, and GnRH in the anteromedial hypothalamus are regulated as a function of the stage of the estrous cycle and the hour of the day. Furthermore, the content of these proteins is regularly higher in the right anteromedial hypothalamus, regardless of the stage of the cycle or time of the day.

Sarcopenia, nutritional status and type 2 diabetes mellitus: A cross-sectional study in a group of Mexican women residing in a nursing home.

AIM: To evaluate the prevalence of sarcopenia and its association with nutritional status and type 2 diabetes mellitus (T2DM) in older women living in a nursing home. METHODS: This cross-sectional study assessed nutritional status using the Mini Nutritional Assessment (MNA). Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People; hand grip strength and physical performance were determined by dynamometry and gait speed, respectively. Muscle mass was assessed using calf circumference. RESULTS: The mean age of the 114 participants was 84.1 ± 7.0 years. The prevalence of sarcopenia and T2DM was 30.7% and 10.5%, respectively. The majority (66.7%) had a normal nutritional status, 29.8% were at risk of malnutrition, and 3.5% were undernourished. The prevalence of sarcopenia in participants at risk of malnutrition and those who were undernourished was higher compared with participants with a normal NS (P < 0.0001). A statistically significant difference was observed in the Barthel Index (BI) between women with and without sarcopenia (P = 0.048). The multivariate logistic regression model, adjusted by age (p = 0.007) showed an association between sarcopenia and nutritional status. Women with a poor nutritional status were more likely to have sarcopenia (OR 4.97, P = 0.003) whilst those with T2DM showed a higher probability of sarcopenia (OR 5.52, P = 0.019) than women without T2DM. CONCLUSIONS: Sarcopenia was highly prevalent in women with a poor nutritional status and T2DM. It is necessary to implement intervention programs to reduce adverse outcomes.

Preclinical Research of Dihydromyricetin for Brain Aging and Neurodegenerative Diseases.

Brain aging and neurodegenerative diseases share the hallmarks of slow and progressive loss of neuronal cells. Flavonoids, a subgroup of polyphenols, are broadly present in food and beverage and numerous studies have suggested that it could be useful for preventing or treating neurodegenerative diseases in humans. Dihydromyricetin (DHM) is one of the main flavonoids of some Asian medicinal plants that are used to treat diverse illness. The effects of DHM have been studied in different in vitro systems of oxidative damage and neuroinflammation, as well as in animal models of several neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. Here we analyzed the most important effects of DHM, including its antioxidant, anti-inflammatory, and neuroprotective effects, as well as its ability to restore GABA neurotransmission and improve motor and cognitive behavior. We propose new areas of research that might contribute to a better understanding of the mechanism of action of this flavonoid, which could help develop a new therapy for aging and age-related brain diseases.

Estrogen Receptors Alpha and Beta in POA-AHA Region Regulate Asymmetrically Ovulation.

We examined the role of the estrogen receptors alpha (ERα) and beta (ERß) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERß-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERß on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated. The number of ERα-ir and ERß-ir cells in POA-AHA varied in each phase of estrous cycle. Either MPP or cyclofenil in the right side of POA-AHA on diestrus-2 day reduced the ovulation rate, while at proestrus day it was decreased in rats treated in either side with MPP, and in those treated with cyclofenil in the left side. MPP or cyclofenil produced a decrease in the surge of luteinizing hormone levels (LH) and an increase in progesterone and follicle stimulating hormone (FSH). Replacement with synthetic luteinizing hormone-releasing hormone in non-ovulating rats treated with MPP or cyclofenil restored ovulation. These results suggest that activation of estrogen receptors on the morning of diestrus-2 and proestrus day asymmetrically regulates ovulation and appropriately regulates the secretion of FSH and progesterone in the morning and afternoon of proestrus day. This ensures that both, the preovulatory secretion of LH and ovulation, occur at the right time.

Chemoinformatic Analysis of Selected Cacalolides from Psacalium decompositum (A. Gray) H. Rob. & Brettell and Psacalium peltatum (Kunth) Cass. and Their Effects on FcεRI-Dependent Degranulation in Mast Cells.

Cacalolides are a kind of sesquiterpenoids natural compounds synthesized by Psacalium decompositum (A. Gray) H. Rob. & Brettell or Psacalium peltatum (Kunth) Cass. Antioxidant and hypoglycemic effects have been found for cacalolides such as cacalol, cacalone or maturine, however, their effects on inflammatory processes are still largely unclear. The main aim of this study was to investigate the biological activities of secondary metabolites from P. decompositum and P. peltatum through two approaches: (1) chemoinformatic and toxicoinformatic analysis based on ethnopharmacologic background; and (2) the evaluation of their potential anti-inflammatory/anti-allergic effects in bone marrow-derived mast cells by IgE/antigen complexes. The bioinformatics properties of the compounds: cacalol; cacalone; cacalol acetate and maturin acetate were evaluated through Osiris DataWarrior software and Molinspiration and PROTOX server. In vitro studies were performed to test the ability of these four compounds to inhibit antigen-dependent degranulation and intracellular calcium mobilization, as well as the production of reactive oxygen species in bone marrow-derived mast cells. Our findings showed that cacalol displayed better bioinformatics properties, also exhibited a potent inhibitory activity on IgE/antigen-dependent degranulation and significantly reduced the intracellular calcium mobilization on mast cells. These data suggested that cacalol could reduce the negative effects of the mast cell-dependent inflammatory process.

Muscarinic Receptors Types 1 and 2 in the Preoptic-Anterior Hypothalamic Areas Regulate Ovulation Unequally in the Rat Oestrous Cycle.

Muscarinic receptors types 1 (m1AChR) and 2 (m2AChR) in the preoptic and anterior hypothalamus areas (POA-AHA) were counted, and the effects of blocking these receptors on spontaneous ovulation were analysed throughout the rat oestrous cycle. Rats in each phase of the oestrous cycle were assigned to the following experiments: (1) an immunohistochemical study of the number of cells expressing m1AChR or m2AChR in the POA-AHA and (2) analysis of the effects of the unilateral blockade of the m1AChR (pirenzepine, PZP) or m2AChR (methoctramine, MTC) on either side of the POA-AHA on the ovulation rate. The number of m2AChR-immunoreactive cells was significantly higher at 09:00 h on each day of the oestrous cycle in the POA-AHA region, while no changes in the expression profile of m1AChR protein were observed. The ovulation rate in rats treated with PZP on the oestrous day was lower than that in the vehicle group. Animals treated on dioestrous-1 with PZP or MTC had a higher ovulation rate than those in the vehicle group. In contrast, on dioestrous-2, the MTC treatment decreased the ovulation rate. These results suggest that m1AChR or m2AChR in the POA-AHA could participate in the regulation of spontaneous ovulation in rats.

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary.

BACKGROUND: Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation. METHODS: Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 µl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB). RESULTS: Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection. CONCLUSIONS: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.