Anti-diuretic hormone (ADH, Vasopressin): This hormone is released by the posterior lobe pituitary along with Oxytocin. Now this hormones secreest due to dehydration or any other problem related to this. ADH (Vasopressin) receptors These are G protein coupled cell membrane receptors; two subtypes V1 and V2 have been identified, cloned and structurally characterized. Mechanism of action:   When ADH (Vasopressin) bind with v 1 receptor they Cause contraction of blood vessels (vasoconstriction), which further decrease blood supply. They also Cause  platelet  aggregation so also helps in blood coagulation. And when ADH (vasopressin) bind with V ₂ receptor they increase the CAMP (GPCR).which further activate AQP2(Aquaprin-2) receptor through which ware transported into blood (re-absorption). They also activate Na+/K+/2Cl- Co-transporter in Loop of henle (↑ reabsorption) Pharmacokinetics Aqueous vasopressin (AVP) is inactive orally because it is d...

Collecting duct Potassium Sparing Diuretics • These drugs give their effect by working is Collecting duct where they inhibits Na+ reabsorption and K+ secretion. These are weak diuretics so mostly used in combination, because filtrate almost 90% reabsorbed before reached to collecting duct.   Machanism Of Action Normally in collecting duct, there are Na+ Channel through which Na+ enter into cells which further transported into blood through Na+/K+ ATPase pump. Now, K+ get back to lumen in exchange of Na+ through k+ channel.   When Potassium sparing diuretics Introduced they give their effects by following two michanism:   i) Aldosterone autogonists.   ii) Sodium channel inhibitors. i) Aldosterone Antagonists Aldosterone is an hormone which bind intracellularly and   increase reabsorption of Na+ and secretion   K+. when these aldosterone antagonist introduces they inhibit the aldoster...

  Distal convoluted tubule (DCT) Thiazide diuretics These are most commonly prescribed drugs. But they also have weak diuretic effect. These drugs give their effect by working in distal convoluted tubule (Dct) where they reduce the absorption of Sodium Chloride by inhibiting Na + Cl -   Cotransporter. Now, In DCT there. Sodium Chloride Cotransporter through which Sodium chloride get in the cell from lumun. Then, sodium get transported to the blood via Sodium Potassium ATPase. While Chloride   Chloride diffuses out on the other side via channel. when thiazide diuretics introduced they inhibit the Na + Cl - cotansporter which decreased Na + Cl - reabsorption and increased urine output. Drug: (a)Benzothiadiazines Hydrochlorothiazide,Benzthiazide,Hydroflumethiazide, Bendroflumethiazide (b) Thiazide like Chlorthalidone, Metolazone,Indapamide, Clopamide Uses - ·        used as diureti...

  Loop of henle This drug gives great derivative effect.This drugs give their effect by working in loop of henle.   Macanism Of Action: It works in ascending Limb of loop of henle.Here sodium-potassium chloride cotransporter is present.which enter Na + , k + , Cl- into cells through which Na + transported into blood via Na + /K + ATPase and Cl - via cloride channel. Now, K+ get back into lumen through K + channel.Due to K + ions in lumen increases,positivety increases in lumen results secretion of mg 2+ ,Ca 2+ into blood through paracellular reabsorbtion.About 25℅ of Na + ,Cl - get reabsorbed into blood in this. when loop diuretics introducid   they inhibits Na + K + Cl - cotransporter and reduce the reabsorption of Na + + Cl - . •These diuretics also inhibit the reabsorption of Mg 2+ and Ca 2+ Drug: Sulphamoyl derivatives: Furosemide, Bumetanide, Torasemide .

 Diuretics (natriuretics) are drugs which cause a net loss of Na+ and water in urine.  According to the site of nephrone diuritic is divided into 4 types.such as:  1. Proximol convulated tube.  2. Loop of henle.  3. Distal convoluted tubule (DCT).  4. Collecting duct.

Proximol convulated tube Bicarbonate reabsorption is initiated by the action of Na + /H + ion exchanger which allows Na + to enter into the cell and hydrogen into lumen part of nephron. In the lumen bicarbonate is Combined with H + and form carbonic acid which is rapidly dehydrated to H 2 O and CO 2 with the help of an enzyme and Carbonic anhydrase. CO 2 enters Into the epithelial cell by Simple diffusion and get H 2 O  to form Carbonic acid by intracellular Carbonic anhydrase. Now, this intracellular Carbonic acid dissociates to forms hydrogen ion and bicarbonate. This hydrogen ion (H + ) gets back to the lumen through Na + /H + ion exchanger and bicarbonate Ion (HCO 3 ) is transported to the blood. When Carbonic anhydrase inhibitors are introduced they inhibit Carbonic anhydrase enzyme which reduces the reabsorption of bicarbonate. Now due to this excessive fluid is excrted out in urine and helps to treat disease like...