Calculations and Glucose Handling in Veterinary Medicine

These flashcards cover key vocabulary and concepts related to glucose handling and renal calculations discussed in the lecture.

SGLT1/2

Transporters responsible for glucose reabsorption in the proximal convoluted tubule (PCT) of the kidney.

RPF (Renal Plasma Flow)

The volume of plasma that passes through the kidneys per time, calculated using the formula RPF = (UPAH x V)/PPAH.

GFR (Glomerular Filtration Rate)

The rate at which blood is filtered in the kidneys, calculated with the formula GFR = (Uinulin x V)/Pinulin.

FF (Filtration Fraction)

The ratio of GFR to RPF, indicating the efficiency of filtration in the kidneys.

Glucosuria

The presence of glucose in urine, commonly seen in cases of uncontrolled diabetes mellitus.

Glucose Titration Curve

A graph showing the relationship between plasma glucose concentration and the rate of glucose reabsorption.

Fanconi Syndrome

A renal disorder characterized by a generalized renal tubular dysfunction, leading to impaired reabsorption of glucose, amino acids, bicarbonate, and phosphate.

Na+/K+ pump

An active transport mechanism that pumps sodium out of, and potassium into, cells, crucial for maintaining cellular homeostasis.

Filtered Load

The amount of a substance that is filtered from the blood into the urine per unit time, calculated as Filtered Load = GFR x [P]x.

Excretion Rate

The amount of a substance excreted in the urine per unit time, calculated as Excretion Rate = V x [U]x.

SGLT1/2

Transporters responsible for glucose reabsorption in the proximal convoluted tubule (PCT) of the kidney.

RPF (Renal Plasma Flow)

The volume of plasma that passes through the kidneys per time, calculated using the formula RPF = (UPAH x V)/PPAH.

GFR (Glomerular Filtration Rate)

The rate at which blood is filtered in the kidneys, calculated with the formula GFR = (Uinulin x V)/Pinulin.

FF (Filtration Fraction)

The ratio of GFR to RPF, indicating the efficiency of filtration in the kidneys.

Glucosuria

The presence of glucose in urine, commonly seen in cases of uncontrolled diabetes mellitus.

Glucose Titration Curve

A graph showing the relationship between plasma glucose concentration and the rate of glucose reabsorption.

Fanconi Syndrome

A renal disorder characterized by a generalized renal tubular dysfunction, leading to impaired reabsorption of glucose, amino acids, bicarbonate, and phosphate.

Na+/K+ pump

An active transport mechanism that pumps sodium out of, and potassium into, cells, crucial for maintaining cellular homeostasis.

Filtered Load

The amount of a substance that is filtered from the blood into the urine per unit time, calculated as Filtered Load = GFR x [P]x.

Excretion Rate

The amount of a substance excreted in the urine per unit time, calculated as Excretion Rate = V x [U]x.

Transport Maximum (Tm)

The maximum rate at which a substance can be reabsorbed or secreted by the renal tubules, typically due to saturation of carrier proteins. For glucose, it's the maximum amount of glucose that can be reabsorbed per unit time.

Renal Threshold

The plasma concentration of a substance at which it begins to appear in the urine because the filtered load exceeds the reabsorption capacity (Tm). For glucose, this is approximately 180 - 200 mg/dL.

Inulin Clearance

A measure of GFR, as inulin is freely filtered by the glomeruli and neither reabsorbed nor secreted by the renal tubules, making its excretion rate equal to its filtered load.

SGLT1/2

Transporters responsible for glucose reabsorption in the proximal convoluted tubule (PCT) of the kidney.

RPF (Renal Plasma Flow)

The volume of plasma that passes through the kidneys per time, calculated using the formula RPF = (UPAH x V)/PPAH.

GFR (Glomerular Filtration Rate)

The rate at which blood is filtered in the kidneys, calculated with the formula GFR = (Uinulin x V)/Pinulin.

FF (Filtration Fraction)

The ratio of GFR to RPF, indicating the efficiency of filtration in the kidneys.

Glucosuria

The presence of glucose in urine, commonly seen in cases of uncontrolled diabetes mellitus.

Glucose Titration Curve

A graph showing the relationship between plasma glucose concentration and the rate of glucose reabsorption.

Fanconi Syndrome

A renal disorder characterized by a generalized renal tubular dysfunction, leading to impaired reabsorption of glucose, amino acids, bicarbonate, and phosphate.

Na+/K+ pump

An active transport mechanism that pumps sodium out of, and potassium into, cells, crucial for maintaining cellular homeostasis.

Filtered Load

The amount of a substance that is filtered from the blood into the urine per unit time, calculated as Filtered Load = GFR x [P]x.

Excretion Rate

The amount of a substance excreted in the urine per unit time, calculated as Excretion Rate = V x [U]x.

Transport Maximum (Tm)

The maximum rate at which a substance can be reabsorbed or secreted by the renal tubules, typically due to saturation of carrier proteins. For glucose, it's the maximum amount of glucose that can be reabsorbed per unit time.

Renal Threshold

The plasma concentration of a substance at which it begins to appear in the urine because the filtered load exceeds the reabsorption capacity (Tm). For glucose, this is approximately 180 - 200 mg/dL.

Inulin Clearance

A measure of GFR, as inulin is freely filtered by the glomeruli and neither reabsorbed nor secreted by the renal tubules, making its excretion rate equal to its filtered load.

PAH Clearance

A method used to estimate effective renal plasma flow (ERPF), as para-aminohippurate (PAH) is both filtered and secreted by the renal tubules, leading to nearly complete removal from the plasma in a single pass.

Tubular Reabsorption

The process by which solutes and water are removed from the tubular fluid and returned to the circulating blood through the peritubular capillaries, primarily occurring in the PCT.

Tubular Secretion

The process by which substances are transferred from the peritubular capillaries into the renal tubular lumen, playing a key role in waste elimination and pH regulation.

GLUT2 Transporter

A glucose transporter protein located on the basolateral membrane of renal tubular cells, responsible for facilitating glucose exit from the cell into the interstitial fluid after SGLT-mediated reabsorption.

Secondary Active Transport

A type of active transport that uses the energy stored in an electrochemical gradient (e.g., Na+ gradient) to move another substance across the membrane, as seen with SGLT transporters for glucose reabsorption.

Filtration Barrier

A three-layered structure in the glomerulus consisting of fenestrated endothelial cells, the glomerular basement membrane, and podocytes, which selectively filters blood to form the glomerular filtrate.

Juxtaglomerular Apparatus (JGA)

A specialized structure formed by the distal convoluted tubule and the afferent arteriole, crucial for regulating blood pressure and GFR through the release of renin.

Tubuloglomerular Feedback

An intrinsic autoregulatory mechanism involving the macula densa cells that senses changes in tubular fluid flow and NaCl concentration and adjusts afferent arteriolar resistance to maintain GFR stability.

Antidiuretic Hormone (ADH) / Vasopressin

A hormone released by the posterior pituitary that increases water reabsorption in the collecting ducts and distal tubules by inserting aquaporin-2 channels, leading to more concentrated urine.

Aldosterone

A steroid hormone produced by the adrenal cortex that promotes sodium reabsorption and potassium secretion in the principal cells of the collecting ducts and distal tubules, influencing blood volume and pressure.